limit

My in-laws have not treated me too well. They've often abused me verbally and scolded me for no reason.I lived with them and served them like my own parents until my husband's transfer but they still treated me like a servant. Now a few months ago i decided enough was enough and told my husband that I'll not go to their place although he's free to go. But when he goes there without me they say things which keeps him disturbed for a few days. Yesterday he told me that he had searched a site and found that it is islamically wrong if I hold a grudge against his parents and dont meet them. I also want to make it clear that they are very egoistical people who've told me often that it would not matter to them a least if I didnt meet them. And now also from wht my husband has told about his conversations with them, its clear that they only want me to come to satisfy their egos. I want to ask if under these circumstances, it is wrong islamically to stay away from them or to limit my visits to their house.

1. What is the time limit for performing the haqueqat (Animal Sacrifice) rites for a newly born child?2. What are the animals that can be sacrificed? Whether a cattle can be sacrificed or not? If yes, can 1 cattle be sacrificed for 2 or more children?3. Do the conditions related to the Eid ul Adha Qurbani, be applied for the haqueqat? If not, what are the conditions related to haqueqat?