Is it ok to NOT invite my sister in law to our anniversary party?

ur doing the right thing! she doesnt deserve to be there until she accepts u into the family just like everyone else did! her brother brought u into the family,and she needs to treat u like ur family,because u are! maybe she will realize when she doesnt get that inventation in the mail how much she is hurting u and how she needs to suck it up and accept u because her brother loves u and she cant change that