Cabin fever with adult children

Well I would be reminding her just whose house it is. As for viruse spraying, just tell her to stop. Everyone is in the same boat with regard to returning to work. Some teachers have never stopped. She really needs to act as an adult rather than reverting to childish behaviour. Stand up to her, it won't be easy but life would be more tolerable for both of you with some new ground rules. This may not be the only lockdown we experience.

My eldest son (38) moved back in with us (husband and me) in December. He's working from home, taking emergency calls from Eon customers. Husband has been furloughed - he's been off 8 weeks now- so they are both here, in my domain and I'm looking forward to having time alone again

Time to tell her enough is enough and to quote Mumsnet, your house your rules.

She is a lucky girl, sharing your home with you while she saves. I do understand you would rather avoid arguments or fall outs but for your own mental health and the fact that you should be able to relax in your own home, a chat is needed telling your daughter her input to whatever you decide to do with your days is up to you and if she has a problem with any of that, keep it to herself, you don’t want to hear it.

It’s a difficult time for everyone Lyn but the last thing any of us need is anyone thinking they are in a position to control our lives. An absolute no, no. Good luck. .

Wow!
I'd tell her to put up or shut up.
She's lucky that you're giving her the opportunity to live and save with you.
Does she make any contribution to your mortgage or Council Tax? Food? Cleaning items?
What d'you think she'd say if you were acting like that in her home...if she had one.
??
Tell her what's what and to MHOB in your home. She's an adult so no need to pussyfoot around her. She'll get far worse from schoolchildren.

Does she go out at all for a walk or a little drive somewhere to give you both a break from each other?

It must be a consolation to you to feel thankful that you are living here and not in some European countries where folk weren’t allowed out for weeks on end until recently!

I think this must be a common problem everywhere LynG6, people are anxious and have varying levels of tolerance. Perhaps as Calendargirl said you should sit down and have a chat. You need to acknowledge her health anxiety and your daughter needs to recognise she is over reacting a little.
Welcome to Gransnet by the way.

She is a teacher; she should have some control over her emotions.
Time for a few pithy words about whose house it is; your house, your rules.

Perhaps you need to sit down and have a good chat. Point out you are glad to have her with you, and happy to be able to help her save for a deposit by doing this, but it is your house, and as long as you are following the guidelines, she needs to remember that.
Sounds like she is overwhelmed by the thought of having to go back to work, and you are bearing the brunt of it.

Has she lived with you constantly since you were widowed? And how old is she?

Probably after all this, she will be ready for her own space, as will you.