Saved daughter's house repossession; now being ghosted

I have an only child, now an adult in her 30s, married and with one child.
I raised her (after separating from her father) to be careful with money, which she used to be. We used to have such a close relationship. Her personality has changed somewhat since having PTSD following a very traumatic birth and she has become extremely reactionary with me in particular, but has had issues with a number of family members and friends - either not seeing them for months and not communicating or relationships breaking down entirely.
Things had turned a corner and she was seemingly coming back to me when she said something to me about her mortgage (it's in her sole name as she owned the house prior to marriage). I asked her whether everything was ok and it transpired that she'd received a letter about twelve missed payments.
Her husband had been paying her money towards it and was oblivious to the defaulted payments. That same day, my husband and I managed to transfer savings and pay several thousand pounds to clear it, saying that we would discuss repayments later. The money was to come from my savings as my husband is her stepfather and I didn't want him shouldering responsibility.
The following day a court order arrived; thankfully the building society cancelled it. They had been SO close to possibly losing their house. I never asked where the money went, but I suspect it went on her apparent obsession with online shopping.
I received several repayments after advising my daughter and son in law to open a joint account (their finances were always separate and bizarrely he didn't have any sort of grip on what was going on and didn't seem to care, being very laid back).
This month, no payment. I'm always scared to ask as my daughter is so volatile. I get this as PTSD can manifest itself in personality change and a lack of self awareness, however I have mentioned to my son in law in an email a specific kind of treatment she could receive (after doing research into it) and offered to talk with him if interested but he appears not to be bothered. I don't want to interfere; I just worry about my daughter as a role model to my grandchild.
I know she has just purchased an expensive item (several thousand pounds) which her husband obviously knows about, yet she is telling me in our group chat that it's 'been a tough month'. What she then does each time is move goalposts in respect of my grandchild (who is staying this week). I am now being asked for an earlier return of the grandchild; it's as if to get back at me for having the audacity to ask politely about the repayment. I'm not made of money and although not at retirement age, I don't have much of a pension due to me when I reach retirement because I cared for an elderly relative.
Recently, I have even been stopped from dropping the grandchild - who I love dearly - at their home. We have to meet in car parks. It feels as if I am being punished and my SIL is being walked over.
What's worse is that there was a recent article in the mainstream saying that going 'no family contact' is a 'trend'. My daughter - although in her thirties - is rather influenced by social media. I wonder if this might be playing a part. I'm a very non confrontational person after being emotionally and verbally abused as a child by my stepfather, so I'm not the sort of mother to step in and say what I truly think for fear of being deprived of access to our grandchild.
Anyone have any suggestions please? No criticisms please; I'm not perfect, just heartbroken and desperate to know if anyone is in a similar position.