My 8 year old SD pees and poops in her pants ALLL THE EFFING TIME!!!!

My DH has had full custody of her and her brothers for 3 years now. Her BM is sporadically in her life dropping off because of boyfriend “trends” but my DH allows her to have her weekends when she does finally come around. So for the last 3 years I have had to deal with peeing. I have had to throw out a $2000 sofa two mattresses and I had to have my car detailed 4 times. Now she doesn’t always pee all the way down her legs like a puddle.. during the day she just drenches the crotch area enough to smell to high heaven at school 2-4 days a week there are very few and far in between days that she is accident free those days the crotch is just a few drops. She pees at school .. (we have to pack extra clothes and baby wipes) So I wash her bedding every day. (I have had her do it.. wash by hand all that) but she poops and does not wipe or actually shits her self and I’m a bit of a clean Person so I’m a bit ocd and I do it right behind her. Because it won’t ever be clean enough I still smell it ...her beautiful princess bedroom she has smells like an elephant den. She is not embarrassed she actually does not give a rip. We wake her up at 12:00am and at 3:00 or 4:00 am she pees in the toilet washes her hands and goes back to bed but some days she actually wakes up dry and will just lay there and Pee in her bed. This has been a rough 3 years. She is sweet and a very bright beautiful little girl her brothers 14,17 are good to her as well however they do tell her “DID YOU PEE?? You smell.. get into the shower” When she does see her mom she comes back talking baby talk 😩 and her regression starts all over again, and well I am just tired. I work full time and I am a bit of a clean freak. Not to mention this is my 2nd marriage (he is absolutely amazing and I wish I would have met him first) he has been divorced from my SD mom for 6 years but he had always had the majority of custody until the last 3 year he has had Full custody of all 3 kids. I have 4 children 26, 24, 20, 19 I have 3 grand sons 3 (potty trained) 2 (also potty trained) and 8 months he is not lol .. I’m 40 and I’m tired. I never had this issues before. I have one son my oldest and three girls NEVER dealt with this. I love my step kids they know this as well I would do anything for them. My 8 yr. SD always hugs me and I hug her back she tells me 10 times a day she loves me and I’m the best and I tell her the same.. but I cry in the laundry room I cry in the shower. I cry on the way to work and I cry at work. My DH is at his wits end too. We have done the Dr. many many Dr.s and therapists and council and just talking and bribing and taking things away and I’m sorry I’m just babbling now .. someone anyone if you have been able to get this burden off.. please tell me what can I do. .. Sincerely a Step mom who wants her step daughter to not be comfortable peeing and pooping herself on a daily 😤😩😢