To think DD would be safer with family than at school?

[cg88]

Both myself and DH are classed as key workers and so are both working at the moment. DH is in daily whereas I work in a school and am on a rota which is currently once a week. Up until now dd (age 5) has been coming into work with me on the days I'm in, I'm in a small school and we only have up to 5 kids in at a time compared to her school which is bigger and has 12-20 in at a time. This has been fine over the Easter holidays because not much has been expected from us work wise but now we're back into term time we have much more involvement with home learning and it's just not feasible (or professional) to be contacting parents whilst DD needs attention, which she does....all the time!
Her school will allow her to attend the days I'm working but AIBU to think actually it would be less risk to take her to my Mum's? Less people, my Mum isn't in the high risk category and would be more than happy to have her, what are people's thoughts?

There are plenty of people who are doing this - they just don't broadcast it on Mumsnet as they'll be told they can't. I only have to look out of my front windows to see this. In one day I saw a grandmother dropping her small grandson back at his house (mum is a key worker so had presumably been working, a separated father dropping his adult daughter back at mum's house and him going into the house (he is also a key worker as is his ex - so neither are isolating), a young adult being dropped back home (I'm guessing possibly from work) by a non family member in a car that us not usually present at their house - need I go on?
People are on the whole taking necessary decisions to accomodate their own needs - that's not the same as deciding to have a bbq and invite your mates around. The idea of lockdown was to SLOW the spread to ease pressure on the NHS - not to stop it completely. In the absence of a vaccine/cure we still need people to catch Covid 19 in the hope that there is some level of herd immunity (as yet unknown).
In your situation OP, if your DM is happy and aware if the risks and she doesn't work (so minimal contact with others) then I think your decision to sent DD there is sensible and appropriate.