Adding a third rabbit to Tilly and Milo

Hi guys,
I am in need of some advice here, I have Tilly and Milo who I bonded last year, and they are a very happy couple.
One of the regulars in my pub had a pair of female rabbits, and one got out of the garden and was found dead the following day in a neighbours garden. The guy who owns the rabbit is looking for someone to take her off his hands for free,he says he feels sorry for her now that she is alone, but he wants her to go to a good home. She is less than a year old,and I was wondering how hard would it be to add her to my 2, is it worth it or should i not rock the boat? He is thinking of putting a free to good home add in the news agents, but I really don't want her to go to just anyone.
If you don't think it's a good idea, is there anyone who knows someone in Suffolk who could rehome this lovely bunny????

I don't really like trios having had an unsucessful one for a year but it very much depends on the bunnies concerned. in mine the two girls just never really meshed, things are better now I have a four although not perfect. If I had my time again I wouldn't not have added to my pair.

I bonded Oreo with a very much in love bonded pair Pink and Nee Nee and they all adore each other. I made sure it was all neutral and took them out for there car ride and was off work the week I did it....and 1 month on now they are out playing in the garden together and Oreo's part of the normal routine....but I have the free hutch, pen and dog kennel if anything goes pear shaped....all is well even though my lionhead is a dominant so and so she was so good and my nethey just adores the new bun won't stop cleaning her !!