Mum's, I need your advice/thoughts!

[Krisvee]

I don't think you're being overprotective at all!! I don't think it matters who it is you wouldn't want them to just take your kids out all the time!
I suppose it's a bit hard until they arrive and you know what they're expecting...Maybe just make sure you chat to dh about it first and let him know what you're comfortable with so that he can tell them what you both expect iykwim?

[Mumma2three]

I would trust your feelings. Having a day together as a fam is great. Would you mind if they had one child at their place for a couple of hours but wouldn't go out? I let my MIL have Coco (she minds her once a week) but I request they generally stay home. i am getting a bit more relaxed, at first I was a mess, but Im having to let go now particularly with an 8 year old.
Take your time and never do anything if it feels wrong. All the best xo