Advice to help best friend

This will definitely be long. Sorry in advance.

I met my best friend (we will call her marcy) about 4 years ago. Shes a few years younger then me but im like the "mama bear" when it comes to people. I always find myself caring for anyone that needs help. She was 17 and didnt have much guidance growing up so a little on the immature side...even to this day. She ended up dating my brother for a few months and he was her 1st. She always took pride in taking care of herself. Very pretty. Then a few short months after that ended up with his best friend and pregnant about 6w later. Both were closet drug addicts (guys&meth). The best friend isaac would put her down because of her immature ways and call her dumb, fat etc etc it goes on and on. And by no way was she fat. She had a great body. She started letting herself go. She wouldnt shower as much, quit wearing make up, no deodorant. She even ended up with bv and wouldnt take care of it...WHILE PREGNANT. She almost lost her baby and thats when treatment started at 8m preggers. Their relationship was very rocky but they tried. When she finally got the confidence to tell him to get out after finding out about the drugs she found out she was pregnant again about 2w later. Same thing as the first with bv and the showering dwindled to about 1x a week because no one would watch her baby. When she spends the night at my place i will take her baby for her to shower. This is about 3 days per month in a row that she stays with me. No big deal. We live about 1hr away from each other so its nice to hang out a few days a month. Now she has both babies. She only showers when she comes here. And i have to force her. Her excuse is 1.) i pay for water so she doesnt want to put me out and 2.) "its too much work and im lazy" her words exactly. She just stayed here for 5 days and i could only get her to shower 1x. I was a little harsh this time though. She stinks bad. She doesnt shave because she doesnt shower and when she showers she is too lazy, she doesnt wear deodorant...umm hello its 100 degrees out and your sweating profusely and it is worse then my old mans bo. She will wear the same clothes for days and when she does change she wont even rinse in the shower and her crotch smells so bad you can smell her 2ft away. She cried when i told her this but i am at my wits end with beating around the bush. She has severe depression on top of that being a single mom and noone to help except when she stays here and she has put on tons of weight. Her own mother tells her she needs to take care of herself and shes getting fat to where she looks like shes 8m pregnant. Ive tried getting her to workout/eat healthier with me, as in weigh in/measure loss as kind of a we do it together even though we live separately and help each other out but she just says she loves food and is too lazy to exercise. I tell her when i had depression the 1st thing i would do in the am is get in the shower, put on some makeup (just something simple like eyeliner and mascara) and put on my fave jeans and t-shirt and feeling a little better about myself helped a little with each day. I dont know what else to do and she wont get help. She got prozac and quit taking them in a week. She swears at her 2yo. Calling him a fucker, falls asleep randomly throughout the day (even when shes here and i have my own 4 kids to tend to on top of her 2yo and 4mo and i have a 5mo) then she wants to stay up past midnight when i go to bed around 9 and doesnt hear her baby cry (his crying has to get into her dreams or she wont hear him-again her words) and i even came out with him upside down in his swing not buckled past out with his head in the blankets because she didnt hear him cry. Im scared for my nephews and her. I would let her stay here but like i said my home is filled and she lives in hers rent free, gets 100 from the apt co to pay gas and electric, gets 500 in fs and 500 in cash ass and still cant make bills a month or provide for her children as well as i know she could. And there is no talking to her mother because she doesnt like me because marcy will come to me for life issues before her and when she did live with me i taught her how to budget and shop and everything and now that shes on her own (baby daddy is in jail-thank goodness because he needs help and hasnt been helping her since 1st baby was 6m) it all went out the window. What would you do?

Sorry if its all jumbled. I didnt preread it.

Edit: ive never told her she is lazy. If you read it you will see that i put HER words not mine. I know that would make it worse and she gets enough of that from her mother as it is.