Oh they sure do!

On Fri 30 Dec 2005 08:28:54p, Thus Spake Zarathustra, or was it Fred?

It's hard to say what adding a companion would do.  Given that each kitty
has a distinct personality, anything is possible.

Having said that, we have 5 cats ranging in age from 13 years down to 1
year, and each was introduced separately (2 are brothers).  They get along
extremely well, play together, sleep together, etc.  Like children (and
adults), one of them occasionally gets in a snit, but that's normal.  

a pound or two is actually a big deal for a cat.  Its 10 to 20% of her body
weight.  in terms of humans that 10 to 20 lbs.  Also, she only eats what you
feed her.  Limit her meals.  She'll get used to it.

I am a huge advocate of one cat is never enough. (six residents and two
fosters at the moment)  If you do the introductions correctly, you should be
able to have a nice peaceful home.  Long time ago before I knew better, I
brought a kitten home and dumped it into the house, and those cats never got
along.  They worked out a peaceful coexistence, but you could always see the
tension.  That kitten eventually became the only child, and professed to
hate other cats, so when the opportunity came around for a second we were
hesitant, but done properly, she resigned herself to the fact he was there
pretty quickly and things went way better than I ever could have hoped.  I
have seen and heard that introducing a kitten is easier, but there are so
many older cats in need of a home that I would suggest you not rule one out.
An easy test would be for you to go spend a couple hours cuddling cats at
the shelter and come home and let your kitty smell you.  Google cat
introductions, and you'll see the procedure and possible pitfalls.  But
again, I highly recommend a second. (and third)

You would be surprised how many cats fit into a lap.

to keep her from getting bored while you are away, you can find toys that
are interactive.  I bought a "treat ball" that you put treats in, and she
has to roll it a certain way to get any out.  Do not put extra food in it,
but a portion of her daily meal.  You could also hide kibble around the
house so she has to "hunt" for her food.  Cat TV is recommended.. videos
with birds and chipmunks and the like..  Spend a few extra minutes in the
morning playing with her with a fishing pole type toy, which will give her
some extra exercise, and make her morning nap that much sweeter.