Worried about kids going to Dad's house during lockdown - AIBU?

[HollyGoLoudly1]

So this isn't me directly, it's a friend.

Basics are: her ex-DH has the kids regularly. No issues, reasonably friendly. Friend has quite severe asthma. Ex-DH has just told her that his partner has moved in for lockdown so neither has to be on their own and they can still see each other. Fair enough except my friend is now worried as the partner is a nurse and will be working in hospital during this time.

She's not sure if the kids should be at their dad's house while the partner is living there. Helpfully, ex-DH is supposed to pick them up tonight and has only just given this information.

YABU - she is being overly cautious, nurses follow strict hygiene procedures etc.
YANBU - the kids should stay with her for the time being or the partner needs to go back to her own house.

YANBU there is more of a risk to the children while she is there, kids stay with their mum. Review situation in around 3 weeks time

My friend has similar issue. Her ex is threatening court to have his 16yr old son to visit. He lives with his partner who is a key worker (medical related) and friend worried about the increased risks.
Personally I think we should be erring on side of caution and plus at 16 he's capable of communicating by tech. However the ex is throwing court threats now. He's going to continue to harangue her.

16 year old can make their own choice at 6 for example I expect court will uphold having to send them

There's no child arrangement order in place. It's always been adhoc. He's never paid maintenance either. I agree at 16 it's son's decision. She's just worried son will be manipulated into visiting even though he doesn't want to go.