so sometimes when my sister comes over and I breastfeed my son, she looks away and says ew and…

so sometimes when my sister comes over and I breastfeed my son, she looks away and says ew and throws me something to cover up with....but yet she breastfed her daughter for a long time, openly. and now she's always saying she is only going to breastfeed for 4 weeks when she has my newphew. idk, if she is being mean or just trying to be funny. but it honestly hurts my feelings...