Over dominating cosister......

Let me tell you the other side of the story from my perspective.

I am the elder DIL of the family and working, whereas my BILs wife is a homemaker. Me and BIL have an excellent relationship and he is like,no not like,he IS my own brother. When I got married , he was doing his final year graduation and he stayed with us in chennai for almost two years in our house to complete his PG. So we share a good rapport .
When he got married 2 years back, I think initially I could sense that my co-sis was feeling a little resentment towards me because my BIL would compare me with her. But I sat down with him one day and very clearly told him that he should stop ANY kind of comparisons with me because that would do no good and me and her are two different persons. I have my good and bads and so does she.

I try my best to make my co-sis feel better , but there are some instances where I can feel that she is frustrated because of me. - like recently when my BIL wanted to travel back to India from middle east(he works there) to visit his new born daughter and my co-sis who was in india for delivery, he told me that he was short on money and the rates were too high for him. He was sad that he could not go to meet his DD . I had just got my tax returns and the ticket was around 500 dollars. So i booked the tickets for him and told him to consider that as my gift for my newborn niece.
When I called co-sis, even though she was happy to see BIL, she told me "Oh already he has time only to speak high of you, now I have to listen to this for all my life". This incident made me understand that not everything that I do with good intentions will make her feel good, so now I consciously avoid doing anything that may be perceived as trying to "show off"(like send BIL and co-sis gifts. Now I make my husband send them or send them in his name and not mine).
I sensed that she feels bad when he speaks high of me, but I cannot do anything. I try to keep my distance, i dont and have never interfered in any of their matters and when BIL and co-sis are around, I make sure that I give them enough space.

She probably thinks I am an attention grabber or I am doing this to get into his good books, and I would not blame her, but the truth is that I do it only because I really care about my BIL and from the past 10 years, he has been the brother that I never had in my life.

I dont know the specific instances in your life that make you hate your Co-sis, but is there a possibility that your resentment towards her is only because your BIL has an attachment towards her? Please note, I am not pointing fingers at you or taking her sides,but could it be possible that she may not be doing this intentionally?

 

OP- gauridinesh has good points. I am younger, working DIL. My SIL is a homemaker. I agree that sometimes I am perceived as a superwoman-taking care of home, kids and work so efficiently. However, I know that is not true.
OP- what I've learned from my experiences- no one can make you feel bad/ inferior unless you allow them to do so. If you feel that she is superior than whatever she does (unintentionally or intentionally) you will perceive it as a show off. She will be your guest. Be a good hostess. Take care of what your guests need, be courteous but don't try to please her or your husband all the time. Find some good books to read in free time or whatever you enjoy doing. If she really shows off- smile and praise.
Good luck!

 

OP may be you need to figure out how to improve your own image in your husbands mind and in family too?
Observe what she does which make others to praise her including your husband.

 

Op
What ever may be your past relationship with her please don't keep referring her behaviour to your DH, she is an individual with her own qualities, she may be smart, a super Mom, etc etc but now she is going to be your guest, treat her as how you usually treat a guest at home, play a perfect host, ignore her shrewd comments and make her feel comfortable, may be after her pleasant stay in your place she would mend her ways or at least she will realize that her attitude din't have any impact on you.