The ad says she's "working hard on her housetraining." Not to mention, when a new dog comes into a house it isn't unusual for the them (no matter what age) to have accidents until it is completely comfortable (I'd give 3 months or more to fully adjust). And she is only 8 months - so you still need to think "puppy" as far as energy, manners, etc. Not to mention, with another dog there is bound to be noise (from play and disagreements) - how much depends on how well the 2 dogs mesh personality wise. My 3 all have great temperaments, but they still have tiffs every now and then and basenji play is loud. Both my adults that I adopted as adults probably took 3 months each to fully settle in and be on sure footing and Ruby and Brando knew each other well before they ever came here.
In your mowgli threads you indicated that you were in school and didn't have time and no mode of transport (think emergency vetting), so honestly, why not wait a bit - especially as this pup is in a nice rescue situation.