She could be looking after an orphan. Not all that rare in the animal world.

Is it possible that she had had twins earlier in the year, and then the third one was more recently?

@cazzie
@ChocolateReigns
Thanks you two.

I asked my son who hunts and he said they can have triplets, so I went googling… among whitetail deer, 67% have twins, 21% have single fawns and 12% have triplets. Source

Yes, lots of blacktailed deer in my area and I think that usually the does have a single fawn their first breeding and twins almost always after that. Triplets on occasion but I have never seen it myself.

Right now I have a doe with twins she has just started bringing around, little darlings! :-)

@netgrrl
@Coloma
Thank you both. I appreciate it.

We occasionally see triplet fawns here; the deer are white-tailed.

@gailcalled Thanks. By the way where is “here”? My friend saw a white tailed one, I forgot to mention that. Does the color of the tail make a difference, I wonder.

West of the Berkshires, on the NYS side of the border. White tailed are the eastern species; mule deer (black tails are a regional version) are the western ones. Source

@gailcalled Something interesting to know, mule and deer. but by difference, I meant in terms of reproduction.