My mum looks after my two nieces a lot (they are 4 and 6) for my sister (single Mum) and will often have them for a week at a time. When my Mum has the kids, there are never any check up calls or similar but to be fair my sister does work long shifts at a hospital. My mum lives close to my sister but when they are at mum's, they are very much 'at hers' if you see what I mean and the kids won't see my sister until they are dropped off or picked up.
My youngest niece has caught flu. My mum was actually quite worried about her earlier and called me as niece's temperature was really high and her throat was too sore to swallow fluids (I live in a different country, but have a DD of the same age who has recently recovered from the flu). I gave advice about what to treat with, what I had been told to look out for etc and my mum followed this. She updated my sister via text at lunchtime. Since then, sister has finished work but there has been no calls or texts asking if she's OK (just a text reminding my mum about older niece's school activity tomorrow) and no visit, even though it would only be a 10 minute journey.
My mum thinks it's a bit off to not be more engaged and is upset at how my sister is acting. She pointed out that I have called even though I was at work. I'm not sure if she's expecting too much (or whether she should have called my sister rather than texted) and was just wondering what other people would have done in the same situation?