My sil and I are friendly but not that close. She is my DH sis and doesn't consider me to be an aunt to her children- just their uncle's wife.
Our kids go to same school. I now work part time hours to pick up my kids every day to save on childcare. She works 3 shifts a week in care home setting. Shifts are 8-3 or 3-10. Her place of work is on the road where we live.
She has never had formal childcare- her parents kept kids when her kids were babies/toddlers despite parent not really being fit. Whereas DH and I paid daycare and CM for years. They can afford childcare and have about 3 times the household income we do.
When sil works to 3, she can't make school pick up time and can be up to 30 minutes late. There is an afterschool club but you have to pay for it. Since September she has asked me to bring her kids with me to her work. I'm there anyway and drive past her work - so why not I thought.
But there are afternoons I may not be going straight home, planned to do errands and have ended up driving kids to her work then back to other end of town again for errands. The requests to do pick ups now come via a text, maybe as late as 1pm day kids need lifted. On 2 occasions when I collected kids they said 'oh mum said you were getting us today ' despite me only being asked 2 hours earlier!
I collected them on Monday, and she's just text and asked can I do tomorrow and Friday. I feel it's just totally become expected of me. I feel I'll be no better thought of by her but again I'm there everyday and most days heading home that way. Friday I always do shopping straight after school- am I being totally awkward to say no as it's driving to one end of town and back again?! It'll add nearly an hr to when I get back into house. I feel I'm just being used as free childcare.