I am really frustrated right now... I try to be nice about things with the boys' mother but I cannot…

I am really frustrated right now... I try to be nice about things with the boys' mother but I cannot take her nonsense anymore. I don't know how it is so hard for her to be a mother and do what she needs to do. She barely has them two maybe three days a week as it is but this week her brother was in town so she wanted them (surprisingly) from Friday after school until today, so I pick them up from school and they both just smell... The entire time they were with her, they didn't shower or brush their teeth... I'm sorry but isn't that disgusting? They are boys and they run around all day, they need a shower everyday. I am seriously baffled right now, and this is not the first time, they barely do when with her. We are lucky if she makes them do their homework. I don't know how you can't take care of your kids... They do everything themselves they just need to be told because they are kids. When they are with us, that is all done every day, they have a cooked meal and attention. Whenever she can't take them or whatever, we have them... So grateful he is such a wonderful father and they always have him.