Everyone has a different attitude to these types of situations, I can only answer this personally. I would not go to the funeral of someone I didn't know, simply because I know someone that knew them. The exception to this would be going in order to support the person that knew the deceased (i.e. your husbands sister) if they felt they needed it and you were both close.
Yes, I suppose that they would be sister-in-laws. Because your sister is your husband's sister-in-law, and the other sister is his sibling, then I suppose they would be sister-in-laws.
There is no common ancestor, so you aren't really related. Related by marriage is one way to describe the relationship.
love marriage is the best because the partners love each other.
No they are not related. they have had husbands i think.
The answer depends on the laws in your jurisdiction and whether your husband left a Will or died intestate. You can check the laws in your jurisdiction at the related question link.
No, she got the second name McAuliffe because it was her husbands second name, Steve McAuliffe.
They arent
Your Sister-in-law
birthday party is related to "gleeful" as funeral is related to somber
I need the Answer for this because my mother wants to know.
No, relatives are relatives either because they are blood related eg uncle, sister or because they are related by marriage eg mother in law
They are related to you by marriage.