Only you can do your own risk assessment, but unless you live in a high risk area, (you can google to find out) your chances of getting it now are very slim.
I am more worried by you saying that she doesn't take your RA seriously, smacks of taking your help for granted. I think the question is 'do you actually want to/feel able to look after them?
What would she do if you had to start shielding again, she perhaps needs to explore other possibilities that she might have to use then?
Go with your gut feeling having weighed up the pros and cons?