I would not make the trade because I prefer to find the dough and buy what I want and accumulate decent firearms. (like you said you do) A G26 is a decent firearm and I can't come up with a heap of reasons to get rid of one. This is my opinion of course, I don't expect everyone to agree with it. Even if she doesn't want it anymore... don't you?
Aside from that argument, I can think of only one reason why I might consider trading it straight up for an LCR-- the only reason that makes any sense to me is that the G26 has been made for many years and there are MANY more of them out there in circulation. Bottom line being, it might be easier to find and acquire a G26 on a moment's notice then it might be to find and get a hold of an LCR.
Beyond that, I can't see why I would do it.
As for it being for the wife, has the wife ever shot an LCR? Or a snubbie revolver? The G26 is a known quantity if she has owned, carrried and practiced with it. A snubbie revolver or an LCR might not be "the" answer she seeks, it may only appear to be. Would stink to get rid of a G26 to chase down an idea that might not execute as well as planned.
As for purse carry vs. on-person carry, that's a whole other very large ball of wax. There are pros and cons to both.
In your position, I would keep the G26 and get her to the range with a snubbie revolver ASAP. See what she thinks about shooting one before making a swap and losing a perfectly good G26.