It's legal yeah but most people would buy a nice property
It might be a lovely property. It's also her home. That word carries a significant meaning for a great many people.
We don't know what circumstances this woman endured prior to getting her council house. She could have been shuffled about quite a lot, dealt with loads of unsettling house moves, been through homeless applications to get to where she is, etc. If she's happy, settled and a paying tenant, why should she have to give up her home? It's a council property she doesn't own. At some point, she will give it back, and somebody else will benefit from it. But for the time being, it is still her home.
The problem here isn't that a woman caught a lucky break - nor does wanting to remain living in her council property make this woman morally bankrupt. The real cause of friction here is that our shitey government aren't doing enough to address social housing shortages, making this woman public enemy number one now that she's scooped a lottery win and is daring to remain in her council house. There's a lot of misdirected anger/frustration here.
The two properties she's bought may be for family/children. She might be trying to do some good and help get those closest to her started off in life, knowing the value of having a secure roof over your head. She might be investing her money in property to help with retirement/social care costs years down the road. Maybe she has every intention of moving into one of these properties at a later date. The fact is, we don't actually know.
It's very easy for outsiders to sit and daydream about the palatial mansion complete with piano shaped carp pond they would buy if they ever scooped a lottery win. But guess what? Not everybody actually wants that. The woman is clearly comfortable where she is. She may be surrounded by a close-knit community and lots of friends and family. I wouldn't be giving that up to go sit in a huge big house all by myself, with only the fucking carp to talk to. How depressing!