Her dancing around with my phone doesn’t fill me with glee either
She won’t dance around with your phone, she’ll prop it up on something in front of her; a bookcase, a mantlepiece. Most inventive I’ve had is a bean tin and a Nutella jar! I don’t know a single dance teacher who would allow them to dance around holding a phone. That wouldn’t be considered safe.
It may mean the dance teacher can only see part of her but that’s fine. Often they work on, say, just arms. Or core body strength so they will look to see if she’s pulling in all her stomach muscles. Or getting complicated rhythms in time to music on the spot.
Maybe tell the dance school you will try it for a couple of sessions and see if it’s feasible and if she enjoys it. Then if you really do find it’s impossible the dance teacher will already be able to see this and can either suggest workarounds or accept it’s not right for you.
It’s difficult for everybody at the moment. All the dance and music teachers I know (and I know a few!) are pretty depressed at going back online. But we are an inventive bunch and really have worked hard to make sure it’s still a worthwhile experience, despite all the difficulties. We know people don’t have ideal houses, lots of space, quiet environments - we don’t exactly live in palaces ourselves either.
One thing I do think people need to remember is that if they want these places to exist when lockdown is over - the dance school/ gym school/ football club/ music lessons - you need to at least try to support it now. I very nearly went back into full time school teaching due to the income drop and my dance teacher daughter was concerned as she had a drop in income that is not sustainable long term - her partner was having to find the full rent on their flat. If the people teaching your children can’t survive, they’ll have to find other ways to do so and the activities will cease to exist.
That’s not a rant at you, OP - everyone is struggling. But if you can possibly keep it going, assuming you value it in normal times, you should.