Namechanged for this because of personal details etc
PILs have saved all their lives in order to give their 3 DCs (my DH and his older and younger sister) a good inheritance.
So a few years ago DH and I found out that we couldn't have children naturally and decided that we wanted to adopt but we were struggling with housing costs. So PILs asked us of we would like the inheritance early as we needed the money at that point so it would be better than waiting.
A year ago DHs younger sister (SIL2) was going through financial trouble after a divorce so PILs offered her share of the inheritance and she accepted.
DHs older sister (SIL1) decided that she wanted hers too because her siblings had gotten theirs early. She didn't really need the money her and her DH have a house and are well-off. PILs were reluctant but she persisted so they gave her the money.
They each had the same deal a third of the money PILs had saved and once it was gone there was no more money. If they managed to save anymore then they might have a bit when PILs die but it's unlikely as PIL are both retired now so aren't really able to save in the same way. They have savings for their grandchildren to be given when they die and the house they live in would also be split three ways for each of their DC.
They gave DH a very large sum of money and his sister's had the same amount.
So fast forward to last month and SIL1 goes to PILs and asks for more money and they say no sorry you have had your inheritance, we can borrow you a little bit but we can't afford to give you anything more. SIL1 was very angry about this and stormed out. PILs were very upset about it so told DH and SIL2 about it but asked them not to make fuss.
The next week SIL1 comes back again and apologizes for her behaviour says she was stressed with work and could PILs just forget it happened. They agree and everyone is happy.
Last week there was a big family party at the local hall for FILs birthday.
Halfway through SIL1 asks to speak to MIL outside. MIL comes back in a bit later in tears saying that SIL1 has told her that she wasn't her DCs inheritance from PILs as well and when MIL said no she told her that she would never see her grandchildren again. MIL was upset but didn't want us to say anything till the party was over.
Then SIL1 got drunk at the pub next door to the party venue and she starts saying that she needs money and PILs are being horrible to her. FIL got angry and asked her what on earth she has spent the original money on. She said fine she would go off and make a list. She left and we tried to brush it off as her being drunk.
The next day she came over to PILs house with her DH and 3 DCs while we were there with a list of what she had spent the money on saying that she had payed off a load of debts that we didn't know about. We were sympathetic but explained that there was just no money left. She started complaint and she went outside to talk to her DH whilst she was gone her older two DCs (18 and 20) told us that she was lying and they had all been told to lie as well or they would be thrown out.
SIL1 then returned and we asked her if she was being truthful, along conversation took place and, In the end her DH said no they weren't they were just trying to get more money and thought the story was a good idea as they thought that PILs were hiding money from them but it was becoming obvious to him that there was just no more money so he would rather come clean. He then wrote out a new list of what they had really spent it on including multiple holidays, New cars , New gadgets, spa days and various other luxury items.
SIL1 said that she was not going to apologise as she feels that she deserved more money than her siblings anyway and she wanted more money as there are things that she hadn't bought that she wishes she had and she wants more money to spent on her DCs education and she feels hard done by as she thought there would be more money to come.
She left saying she wouldn't forgive PILs for pretending that there was more money to come when there wasn't but PILs say that they never told her that there was more money.
So is SIL being unreasonable and what would you do now?