Moms what do you do in my situation? Help

So my sister in-laws came over the other day one of their sons is around 2 yrs they jump in my couches i tell them in front of his mom no don't do that couches aren't for jumping around but won't listen. His mom (my sister in law) is literally next to me and doesn't do or say nothing. She just grabs him puts him down. Then he does it again and here i go telling him. My other sistet in law her kids were there too but shes more strict on them. Bit Its like omg what do i do with my other sister in law if her kid don't listen and she won't do nothing either? I mean i find it rude