Hi Chameli,
How are things going now? A little better? Any improvements? Have you told your husband that before agreeing to do any future babysitting for his sister, he should ask you about it first? If so, how did your husband respond to it?
Perhaps this will sound mean, sneaky, and manipulative. But let's face it, many of us are guilty of using this technique at various times in our lives to get our point across to the other party, and to display our seriousness about an issue. And SOMETIMES (maybe not all the time), but sometimes it can works! Chameli........how effective is a COLD SHOULDER with your husband?
Maybe he also doesn't stand up for you because deep down he feels that you WILL ALWAYA be NICE enough to ALWAYS do what his sister orders, ahem I mean requests you to do. Time to show him that it's not just a complaint you have, it's a serious issue!
You and your hubby need time to bond as a couple, you need time to go out watch a movie, eat at restaurants, or just chill at home ALONE. It's unfair of your sister-in-law to get in the way of that. And I hope that when YOU have kids of your OWN.....that your SISTER-IN-LAW will be nice enough to RETURN THE FAVORS and BABYSIT YOUR KIDS FOR YOU AS WELL!!!!!!!