Don't be silly.
In your OP you say that it is going on the market for 400k and presumably 50% of that is yours.
With £200 000 there are places you can buy outright.
Even with a £100, 000 downpayment you can definitely get a mortgage for a place you live in yourself or rent out.
"I don't want to be a landlord!"
You pay an agent. They take 10% of your profit. It's their job, like being a mechanic or a doctor. You never have to go there or do anything. You just see the money in your bank account and buy things for your children.
You're being hard of thinking.
And yes, it was all 30 years ago, but your chaotic thinking shows you're not over it. Speak with a professional.
"I can't afford to buy" Yet you want to be lady bountiful to this random family so THEY can buy.
We had to move out when our landlord died and the person who inherited sold the house. Your children are not in a stable living situation. You have a chance to give them that. But you want to give that chance to random people instead of your own actual children.
Maybe you get off on being praised. "CrazyBatIknow is so amazing! She gave away a whole house! She's mother Theresa, Princess Di and Batman all rolled on one!"