Sherry.......Good luck on making others (sister in law) understand your reasonings for not wanting to care for your sick nephew. First comes the  dedication to keep your child well. If she lives with her in-laws why can’t they help her on days the baby is sick. Do not feel bad as from what I am reading between the lines is THIS MOTHER does not provide proper care for her own child then she obviously will not take heed that YOUR CAH child cannot and should not be exposed to others who are sick. It is hard to WANT to help out family and have to draw the line when we need to protedt our own, She may get huffy for a few days ...but she will not blow you off. She needs  you and the possibility that you can help with her child later on. Let her steam for a few days and offer a playdate when her child is well. This will blow over...but the issue will come up again. Stay firm on your decision to keep YOUR child HEALTHY...... Good Luck.

 Cherry also from Virginia