I doesnt like my sister-in-law behavious with me.she always do two faced things.whn my husband and?

brother-in-law is in home she behaves differently and with me she behavies differently.she use to trash alot of food and doesnt eat the things which i make and next day she use to make things byherself and eat.i feel very bad for this.after i make something and when i am not in kitchen she use to come and make something else.if she tells me earlier only i wont make the things.she is pregnent and do all hardwork.she use to bend alot and use to stand on stepper and takeout the things,but whn my husband will and brother-in-law is in home she use to ask me to pick out the things,bcoz of her such things i use to quarrel with my husband as i doesnt like her changing behaviour.bcoz of all this problems i am not able to conceive also.my parents tells me to avoid her but daily seeing her bad works i am not able to concentrate in mylife.my husband love me and care me so much but since there joined us 3months ago we both r very much tensed by her and my husband too doesnt lik her behaviour