yes if your mean behave by not coming on to her there behave and if you mean just being polite be polite you don't know how long your going to have to put up with her so you might as well be nice to her.
Sister In law
No. The elder wand is the most powerful wand in all the wizarding world.
The brothers of your husband are your brothers-in-law.
The 'Elder Brothers' refer to those intelligences further along the path of spiritual advancement than the mass of humanity as it now stands. The Elder Brothers are all Self-Realized Masters who are guiding mankind to the culmination of spirituality within.
If grandfather transferred his property to the elder brother then the elder brother is the owner. Generally speaking, the other brothers have no right to any share. The other brothers can ask but the elder brother doesn't have to share the proceeds. If the other brothers believe the elder brother exerted undue influence to obtain the property they could sue in a court of equity.
yousuf pathan
He has a elder brother.
sister in law
Horus the Elder, Osiris, and Set.
Morne morkel is elder to albie morkel.
They are brothers. Salman is elder , followed by Arbaz Khan and the youngest is Sohail Khan.
Rajinikanth has two elder brothers and a sister.