Carla,
Just in case you didn't know - you don't have to let her in. She has to offer a service but you are not obliged to accept it - and there won't be (or shouldn't be) any comebacks on you if you do decline her.
Hope it went okay today though. What's she like?
Mine is very nice thankfully and doesn't notice all the disorganisation (toys everywhere, no hoovering or dusting done etc). And as a HV myself I never notice these things in other peoples houses which are often tidier than mine - and they've often got several kids. Puts me to shame.