Don't worry, it didn't cost me anything as everything I got was from searches in the index, which is free, on the official 1911 website (www.1911census.co.uk/). I didn't see any images.

Unfortunately I don't know the address - I hope I've posted everything I found out - but it was in Douglas. Using the index alone you have to have something to start with - it'll confirm what you know already or guessed. I guessed the grandparents were born in Peel and it said three were. If I'd worked my way through the parishes it would have confirmed Kirk Michael for the other in the end, if that's what she wrote.

You already gave their addresses in Peel so I put those into the search box for 'Residence' and it came back positive. I did the same for Allen St, but it was a negative. I guessed their marriage date from the first listed child's age and worked down from +/- 5 years until I got the exact year.

I'm afraid this still doesn't help you with your original query of which grandparents looked after your mother, or when they moved to Liverpool.