My sister and her family visited last October... boy was I glad to see them off at the airport. They moaned about everything. It got embarrassing as everywhere we went, they'd have something to complain about, especially in restaurants.

My mum is planning a visit next year and to be honest, I can see that going the same way. She's a perpetual moaner who only sees the negative in everything.

Sometimes I wonder how I turned out to be so normal

As a visitor, I like this approach too - I like to hire a car & then wander off - meeting evenings / weekends - but then if not in Canada this is my normal travelling.
Also it is not always so easy if the older parents not keen on driving - my Dad for example is fine if I am there too & we are together, but would feel a bit dependent if had to wait for my sis to drive him around.

p.s. As an accompanying traveller to my Dad he can do my head in too - the second transatlantic trip he got a lecture:
yes the plane will probably be late, yes it is annoying, BUT saying so for hours will just annoy me so just accept you can't change it & so please be quiet
ditto inefficiencies you observe throughout the trip, ditto where things go wrong, etc etc.
has worked a lot better since

doesn't solve it all, but he never travelled much so had high expectations of this uber efficient trip with no probs

We have been here 5 years, my Mum hasn't yet been well enough to make the trip here (cancer and complications). She was going to visit this summer - dates were discussed and she even asked if she needed to bring sunbathing towels But she ended up having another op. I am going to see her in two weeks. I can't wait to see her, she cried when I told her I was coming, she wanted to come here.

I have no idea how we would cope with my Mum and Stepdad for two/three weeks but by god I'd love the chance to find out.

To the original poster - just bite your tongue and get through it. She's your mum after all - the only one you'll have and one day she won't be around any more, then you'll be sorry.

Yes, this is a very good approach and we have had some visitors that have done just that. It seems to be the older generation who are reluctant to do this plus my mum doesn't drive, never has, so is dependent on us to take her out. Another good option that worked well when my sister and her grown up kids visited last year was we all went off together for a few days to Jasper where none of us had been before.