You should keep the cat. Just give her more love and attention, let her see the
baby. No one will adopt an old skittish, shy cat with litter box issues.

I agree with Mary.  This cat needs some extra love, and the fact that it is
declawed may be contributing to the litter box problems.  Treat her as a
"sibling" to your baby son to show each her that she is not being displaced.
The likelihood of finding a new home for an older cat with litter box
problems is slim, and you owe it to your cat to return her years of love
with some additional attention at this time.

MaryL

MaryL

Call your local humane society. Ask them honestly what her chances are of
finding a new home with her age and issues (this is kitten season in full
swing, and most shelters are currently brimming if not overflowing with cats
and may just not have room, and if they do have room, an appointment is much
preferred over walk-in surrenders). Some of them now offer a "rehoming"
service that allows adopters to see what animals in the community need a new
home. Otherwise, they may have a behaviorist on staff who can answer
questions on how to help your senior kitty adjust to having a new baby.
Consider this behavioral issue the same sort of thing as an older child
acting out over a sudden lessening of attention for the same reason. It CAN
be resolved without giving your kitty up.