You're absolutely right. Kids will learn nothing if the parent just drives across town to deliver dumb stuff they forgot at home. It gives them no incentive to want to remember things when they know the parent will bail them out each time. It does the kid no favours 

"She's generally a good kid..."

but also, "jealous of our two kids I think and sometimes bullies", "she whines and acts annoyed in the morning when you tell her to make sure she doesn't forget (acting like it's crazy that we say anything) but then forgets..." It won't change if DH and his ex keep falling all over themselves running things back and forth. And the bullying of younger siblings by a teen needs to be addressed. 

And this girl is almost 15. This post should be called "how to turn what would otherwise be a good kid into a rotten Mean Girl." 

Happened in my case as well.  You may need to try the strip at the door method to alleviate some of this.  When she arrives make her strip down all her clothes and her belongings go into a bag then she puts on the set of clothes you have for her at your house only. When she is ready to leave, get out the entrance bag and send her off with everything in the bag that she came with.  

Yeah she's a little old for this but it will teach a good lesson.  I have clear memories of running to SD's school with her backpack and school books ( not that they ever studied or passed courses or even attended school half the time)   because she  so called "forgot."  I had to go into work late because of it which was at a job that had the long knives out for me anyway.  That job being our only source of household income due to Chef paying almost all of his income in CS.   Boy that cheesed me off!

Ot how many times they so-called forgot laundry items at our house when it was really in piles at the Girhippo's pigstye.

No you go without or BM can come collect said items off the porch. Time to teach her that is you forget your laptop at work, you  can't make that presentation to the boss... if you forget your calculator for your college exam, you fail... if you forget your ID, you just wasted a trip to the DMV. 

My guess it after a couple weeks of having to suffer the consequences she will be remembering everything that she needs for the week. 

Honestly I want to bash my head against the wall watching these delusional daddies complicate problems that could be quickly and easily solved with a simple "NO"

ETA:  I also just wanted to say that it's a good time to learn now when the stakes are low

I can identify.  In the EOW weekends, SDs used to either leave stuff at BM's that they wanted at ours, or leave stuff at ours that they needed for school.  DH was forever driving up and down with these things - I used to tell him not to, but it made no difference.  

It sounds like it would  be worth your DH going through her stuff the morning of.. or eveneing befor to ensure she hasn't forgotten anything..since he is the one who will be running things.

He could also start having a backbone with BM.. "no.. she wants it.. you get it."

I'm assuming it's more than a 15 minute drive to deliver each way?

I like the idea of your husband being more firm with bio mom and saying, if she needs it we have it in a bag on the porch. It would be great if he could be more firm with his kid and not deliver things to her. You could try explaining that she won't ever learn if she keeps having items delivered. It gives her no reason to try to remember things. That in life she needs to eventually get better at bringing what she needs places. Etc etc 

My OSD magically stopped forgetting things when DH finally said NO and she didn't have things for school (I think she was in 5th/6th grade. The drive was 1.5 hours ONE way. He did get sick of it. She continued to lose personal things though, esp. the house key which I made a huge deal about because he then had to leave the door unlocked for her. I mean, really? Because a kid cannot even keep a key (YSD never lost hers)? There were no ramifications then and I was about ready to go with a keyless system when she PAS'd out.

The next time this happens and you know it will....do NOT say a word. Don't offer to find the item, or bag it up. Don't offer to drive it over to BM's or to school. Let dh figure it out. It's called drop the rope.

Just say OK darling, drive carefully BYEEEEEEEE
 

IF dh brings it up that he is tired of running around---just say Uhhh ahh, mmm hummmm, smile---Lets go out to eat darling ok?

UGHHHH sorry this is going on. 

I have a really forgetful 11 year-oldest. Incredibly smart academically, has the emotional intelligence of a 40 year-old, sweet tempered and likable. But the phrase, "she'd forget her head if it wasn't attached" could have been created with her in mind. It's mind-boggling how forgetful she is. But her dad and I have been firm about not going out of our way to bail her out, and that has helped so much. She's learned to write herself notes and sets Alexa reminders to help her remember things. She's also learned to prepare the night before for the next day. It took a lot of work and trial and error to figure out systems that worked for her, but ultimately we made it her responsibility and she rose to the occasion. Now when she does forget something, we're a lot more likely to help her out because she is actually trying.

There is no way in hell I'd be running all over town helping a teenager who isn't even making an effort. She's going to be in for a rude awakening when/if she leaves the nest.

My SO would do this too, run stuff to them. You can walk to BMs house from ours and I would say to make them walk back for it. Nope never happened. At least they stopped staying with us so they can't leave stuff here .

Generally a good kid.  Hmmm?  Other than that Mrs Lincoln, how was the play?

Time for SD to learn responsibility and do without whatever she forgets until she returns for the next visit to that home:

With the exception of life sustaining meds, it sucks to be SD when she forgets her shit.  Forgotten home work. Tuff crap.  Forgotten sports uniforms.  Tuff crap. 

Lesson time!