Does my cat need a friend?

Well, it's official.  I have another granddog.  My daughter and her husband decided that their dog Stella, a two year old boxer, needed a friend so they have rescued a six month old pup (mixed breed) from the SPCA and named him Wallace, Wally for short.  So now I'm wondering if my cat, Frances, needs a friend.  For several years Frances was one of three cats.  The other two have passed on to kitty heaven, and now, at 12 years old, she's an "only cat" but she really doesn't seem to mind.  She always seems happy to see me when I come home and spends a lot of time sitting beside or on me when I'm doing things like writing this blog.  I really don't think she wants to share me.  Oh good, I've talked myself out of the feeble urge to get another cat, at least for now.