[HairOfTheDog]

Rosie can use the newnewguy for an opening with the sister if that is more within her comfort zone...

"Say, sisterofguyIlike, there is this newguyImightlike who I have been talking with, but I just don't know.... it has made me realize that I really like your brother... and I wouldn't want to go too far down the road with thenewguyImightlike until I have at least explored it.

[Wneighbor]

Definitely something to explore.

Also, how about

Yes friend, this is really interesting getting to know newguy in email etc. but, I'm a little hesitant to try developing a relationship with someone over a distance. I mean, if I knew he was a great guy like your brother............