Mess Perfect 2 - 152

Actually, Tali and Legion did not agree to be friends that exact moment; they just agreed to a truce so their fighting would not impede their mission against the Collectors and the Reapers.  Tali then decided to take the extra step and offer an olive branch, most likely for Shepard's sake, which could then lead the path to friendship later on.  At this point, Tali and Legion are not friends, but they have reached an understanding with each other.

So with that in mind, I think it *did* make sense.