I don't think you are being the least bit unreasonable Ribena and, furthermore, I think a lot of the people here, who've responded to say you are, are being utterly ridiculous!
You did not invite your MIL to stay. Therefore, if she wants to visit, you are not responsible for where she stays. It really doesn't matter what she has or has not done in terms of helping you, how much she loves her grandchildren, what the colour of your sofa is, how many bedrooms you have, or how many generations of some family ever lived in one room and loved it. It's all irrelevant.
AND I think having a tiny baby and a preschooler is hard work and I completely understand why you don't want visitors.
AND for goodness sake, how can anyone say a baby just seven weeks old is not a new born - of course it is! And what a mother needs to do to cope at that time is entirely down to the mother.
AND the house sounds small. I don't see the obvious 'spare' room. I am laughing at all of the offers of suggestions to rearrange your furniture - it's your frigging house OP so you don't need to move a thing that doesn't work for you and your family. If you want to wait a month or two or twelve before doing the whole sofa bed/ blow up bed thing, then that's your call. It's not unreasonable - it's what works in your family.
AND all families are different - why on earth is everyone projecting their own family dynamic on to the OP and getting angry because she is not responding as if she is in the same situation??? She's not - it's her situation and clearly she's not happy about MIL staying just at that very time. So MIL doesn't need to stay just at that very time!
AND to all the people who are some kind of wonder woman, happy to host guests and squish up and totally re-organise the house so as not to come accross as being unreasonable (or a 'porcelain Madonna'
) while exhausted, breast feeding a 7 week old and probably still bleeding - well done you! Marvellous! But we're not all such 'together' earth mothers, so be a little accommodating and accept the diversity of womankind - some of us are shattered and fragile less than two months after birth.
I'm reeling at the narrow minded inflexibility shown on this thread, tbh. In fact, I rarely respond to threads anymore, but was irked into doing so.
Have a go at me instead now... Cheers! 