I think the worst part in it all is that she has introduced a new man into the children's lives when they have just lost their dad.
If my husband died and 8 months later I felt ready to date I simply wouldn't as it wouldn't be fair on my children
Obviously we're all different. I'm 6 months into a break up and I'm not ready to date yet...on that basis I can't imagine dating that quickly after a bereavement.
My ex's mum had the same condition as Tom, and died 3 years ago within a month of diagnosis. It was very sudden and shocking for everyone. Within about 4 months her husband of 50 years (my Ex's dad) got involved with a woman. This caused a lot of upset to my Ex and his siblings, especially because their mum didn't like this woman one bit (for good reason). Thankfully it all fizzled out after a few months, and I think in hindsight he would say it was far too soon.
Thing is, all the children in that situation were adults, and they were still upset by their dad's decision at a point when they were still grieving the loss of their mum. I can't imagine how Tom's tiny kids must be feeling, first they lose their dad, their mum disappears for weeks, and now there's a new bloke in the picture (who's a convicted killer) - whether or not she's introduced him, and I expect she has, is a moot point because it's just another thing that takes her attention away from her children.