This is interesting, as at our age, we have been on both sides. As a young mother, I was in hospital for ten days after a difficult first birth and there were quite strict visiting times but had I immediately been at home I am positive I would have wanted to cherish time alone with just my husband and baby.
Now, of course, I see the flip side to that and hope I was sensitive to my daughters' needs (two!) to leave them time for their new family whilst enjoying the GP role.
So, a tricky one. I would emphasise (or, hopefully, have your husband emphasise) that whilst they are very welcome, you are tired and if they come it would be to see what they could do to help your situation rather than just purely sit and coo over the baby.
I feel very strongly that a GP's role is to support that of new parents, nothing else. Offer some small refreshments and after half an hour, if there is a small job to be done, ask them to do it (shopping, hoovering, anything to keep the wheels turning). Hopefully they will feel wanted, included and part of the new family dynamic.
Suggest they return in six months/a year, depending how feasible their journey is, so they can continue the family adventure but please do not feel you have to do anything you don't want to do. If they really care about you and your husband, they will want to fit in with you and help.