I'm 14 weeks pg with DC2 and work full-time. DH has three sisters, one younger and two older. The younger sister lives with her DH and FIL. FIL is in his 80's and somewhat infirm and doesn't look after himself. The idea was that FIL would move in with her due to these issues and contribute towards the rent so that he could be near family and she could get a bigger house. The original idea was that younger SIL would buy a house (FIL gave her a significant deposit and would be contributing to the mortgage) but she decided to rent instead.
They used to live very close to the other two sisters and us which was great in terms of being able to drop in to check on FIL, taking him to the doctor, to get his hair cut etc. They've recently moved 15 miles away to a bigger house; DH counselled against moving so far away as it would be difficult for the rest of the family to help look after FIL but she ignored him. DH went to visit his dad last week and found the heating turned right down, no fridge (they hadn't bought one yet) and barely any food in the house. He turned up the heating and resolved to speak with his sister about the situation. Youngest SIL called him that evening berating him for turning up the heating in her house (it really was freezing in there!) and told him to mind his own business. She still has the significant sum of money that FIL gave to her and has started spending it on things such as a huge television (they already have a huge television...).
Older SIL dropped in on FIL yesterday and found that he was smelly (he finds it difficult to get in and out of the bath so the new place has a shower cubicle for him to use), the milk was frozen in the fridge, there was still no food in the house and that two of FIL's medical appointments had been cancelled because younger SIL didn't have the opportunity to take him. She called DH to discuss and DH quite naturally, started to get worried about his dad's welfare.
DH is now talking about his dad living with us instead and getting our garage converted into a room for FIL. I told him that there was no way that I would be the main carer for his dad as I would have a 4 year old and a new baby to look after during mat leave. He insisted that wouldn't be the case but when pushed, acknowledged that as I would be on mat leave, I would be the main carer. I'm just fuming that his sister doesn't seem to give much of a crap about his dad and expects the rest of the family to do 60 mile round trips to do such things as take FIL to the doctors, get his hair cut etc. Not one of the family confronts her about her behaviour ("I don't want to get involved" is the family motto it seems) and it seems that I will be the one taking on all of the burden.
I'm pretty sure that IANBU but would welcome perspectives and advice.