Please keep it fair Op – either giving it to each when they buy a house – or making amendments in a will to even it up (but if you feel DC1 and 2 have had equivalent already, state that).
I bought three houses alone in my 20s/early thirties then a joint one with DH in mid thirties - with not a bean of help offered at any point. It was the days of 100% mortgages, so didn’t need a deposit for first one, nothing was offered, even to help with furniture/fees etc, but I had a job so could pay my way.
DB has not worked for most of adult life, pure laziness, always had to rent – he asked (or rather bullied) our mum and got a huge deposit (about a third of mum’s cash savings) when his wife wanted them to buy their rented house a few years ago (they got a mortgage by other means)
I found out by accident, also found out she was giving them a large part of her pension each month.
It wasn’t about the money, DH and I have enough – it was the secrecy and overwhelming feeling of him being the favourite. “But you never asked” was what I was told. No, but she could have told me and attempted to make things right in the will. Other members of the extended family knew and were sworn to secrecy, which made my hurt even worse.
I was NC for a while, trying to process my feelings but she was by then terminally ill so I couldn’t sustain the NC.
She did give us some money before she died, but it felt like an afterthought. I knew it would never have been given if I hadn't found out, and DB would no doubt have gloated when she died (she had kept the transfer paperwork!).
Unfortunately it sullied my memories of her last years, and more importantly, those of my kids. They adored her but as young adults, saw the hurt and upset that her actions caused me. I have vowed to treat my two the same at all times.