S in l wants to visit with 2 children.How to say no to other SIL who wants to come too

[limetrees32]

Other SIL is v difficult and manipulative and not sure that a flat not enough beds will work.
Difficult SIL. will try and manipulate nice Sil

We only have room for one set of visitors at a time.

Tell her there's not enough room, sorry, and stick to your guns on it.

If nice SIL says she'll share her bed with the other SIL, you can say there's not enough space in the living room, not enough bathrooms, doesn't matter if it's a stupid reason, your home, you decide.

Three questions. 1. Why does “other” SIL want to visit? 2. How does “other” SIL know about the visit? 3. What does DH say?
Personally, I’d postpone the visit; that solves the problem. If nice SIL has any sense she’ll realise why you’ve postponed the visit and not make the mistake of letting the other SIL know about any future visits.

I'd leave it to your husband to tell them, assuming they're his sisters.