Well, I'd have thought it unlikely if she's a trained carer, but I understand your worries. If there's anything at all negative about your meeting would you be able to ask for a different carer? You certainly don't have to accept help from someone you don't feel comfortable with, but I'm not sure how you'd stand if you asked for someone else.
Whatever your reservations, I hope they come to nothing it's a successful visit. Wishing you luck!
Will she be able to spend some time at first with all of you, getting to know DD and the family? I think that would make her feel better and do the job better and make you feel better too. Although its tempting, no point in rushing it. But also make sure she does things with/for DD on her own quite quickly too.