Sitting on a sofa which was messed with urine

Q: My wife is suffering from a serious disorder about purity. This is all due to urine.

If a child has urinated on a sofa and if someone sits there after its dried without being cleaned, will the other person be impure? Does he/she have to change their clothes?

If he/she sits somewhere else with those same clothes, would that place also be impure?

My wofe is really not well because of this and she’s always washing things, beds, clothes. etc. 

Receiving items of inheritance as a gift from the heirs of one's friend

Q: I am an expat in Saudi Arabia. One of my friends passed away here last December and his family had to move back to India. They sold most of the major items and got money and the remaining smaller items they gifted to others (Example: dinner plates, a wall clock, 3 unanimated wall hanging sceneries, etc. they gifted us and few items to others also).

Is it Ok to keep and use those items or must they be donated in charity? We are not need in need of those items and we just kept those items because we were very close to that family. What is the better option?