My own mother made it very clear that she didn't ever want to have a big part in the lives of all her GCs, my sisters and I found that very hard and it still upsets me. now that she is in her 80s, all of a sudden she is asking why her 9 GCs never contact her - they don't know her!
However, all four of us have had the most amazing MiLs. They are/were (some now dead, others casualties of broken marriages but still around and still in contact) brilliant grandmas. DBH's DPs have only just sent my DD (a step GC to them) some money to help with her study fees.
I get on really well with my GC's Nanna. She is lovely, and I am so grateful to her for looking after DD when she has been very ill a few times, as I am too far away to be able to do much. She looked after each GC at least three days a week, and as they are good, kind, well-behaved children I reckon she deserves some of the credit for how they are. I have them up here for a week three times a year, she has been here too. Sadly she has been very ill lately, my DD will be distraught if anything happens to her. So will the GCs.