Mother in law in assisted living: family's expectations of us to foot the bill are unrealistic. Any advice?

I am a somewhat newly wed to my husband of 11 months. So far our marriage has been wonderful. He's active duty and we recently found out I am pregnant. There have been some complications which have kept me from working. Mind you, I have every intention of going back to work after I recover from pregnancy. Recently, his mother has taken a fall and cannot care for herself. At 60 years old, she has a history of epilepsy and stroke (among other health conditions). This keeps her from using one side of her body. She has been on disability for years and offered to go to assisted living (but refused). With her recent fall, it has been impossible for her to care for herself. She barely could before. Meanwhile, we are states apart, and cannot be there to take care of her. We can't sign anything for her. We can't oversee much, but we help out financially where we can. When my husband was recently near his family's town (for 2 months training) the family agreed that my husband's mother needed assisted living. His mother also agreed that at some point she would as well. What a milestone! We were happy she finally understood she needed help. Within a week, the grandmother (husband's mother's mother) had picked out an assisted care facility, did not consult my husband, myself or even her daughter (my husband's mother) about the expenses. It was the best (and most expensive) the area had to offer (and that's why she chose it). Instead of waiting for Medicaid and Medicare to kick in to cover the expenses (husband's mother is on a waiting list), the grandmother and sister of my husband's mother signed her over to a room at this place and she was moved in quickly. This all happened within a week. My husband and I were confused by this. None the less, we agreed to pay $1200 for the first month, and only the first month, to cover half of the expenses. This came out of our savings. Meanwhile, we were left confused as to why this decision was made so quickly. Usually assistance takes time to set in. My husband's grandmother (his mother's mother) is still able minded and able bodied, but meanwhile expects us (newly married, baby on the way, student loans, and moved twice in one year) to pay help pay for half of these expenses. The total expense of the facility is 2000 dollars a month and we are expected to pay for 1000 of that. It's something we did not sign for and have no way to pay for regardless. We have no legal contract with the facility. Meanwhile, my husband has an older sister (also states away) that's helping out where she can, but also cannot afford the amount. The mother's side of the family doesn't ask her for her money, because they know she doesn't have it. My husband has long taken care of his mother where he can, being active duty, but he simply cannot be there. He may have had more money to spend freely while single but can no longer do this as a husband and soon to be father. His mother's side of the family places expectations on him that can no longer be met. Meanwhile, we were waiting to make our pregnancy a surprise for everyone. The plan was to wait until he returned home with me and we would call everyone with the good news. Unfortunately, my husband and I agreed to reveal this to his mother's side of the family about the pregnancy. This was in order to explain why we couldn't pay that 1000 dollars a month. Naturally, my husband's mother was delighted, however the grandmother didn't congratulate us and stated that "babies/children are not that expensive!" The grandmother tried to guilt trip my husband, threw things at him, and tried to slap him, when he would not agree to pay for something he did not sign for or conditions that were not agreed to. I, my husband, and the rest of our family (on both sides) feel the grandmother is trying to take advantage of us (specifically my husband) for something that was done in haste and without anyone's consideration. She signed the contract and it is now her responsibility. Meanwhile, the grandmother, and my husband's mother's siblings are upper middle class (with summer homes) and live close by. Although I do not know what bills they have to pay, they're not starting out in life with a new marriage and babies on the way. However, we are still expected (as a one income family) to foot the bill. And we refuse. I understand his grandmother is elderly and desperate to get help for her daughter, but doing things in haste and expecting others pay with a baby on the way is thoughtless. My husband is upset that I was not even considered in this decision making and his grandmother does not care about our family. Meanwhile his mother does not expect us to pay for a place she doesn't even want to be in. At this point in time, my husband and I have decided to make visits to his mother's side of the family short (only with this mother) for the lack of concern for our child, finances, and marriage. What a mess.