Bringing kittens into home with older cat

We have a 12 year old female tortoiseshell cat, and would like to bring two new kittens in to the home. Our 14 year old male cat that also lived with us passed away recently. She does not seem badly affected by this. Do you think it will alter her personality if we bring new cats in at this point? And would 1 male and 1 female kitten be the best choice?
   
Thank you for your feedback.
   
Joanna.

Every cat is different but I am going to take a stab at it and say that she likes being alone and will not react well to two newbies.
   
But take a shot and see what happens, as long as you are in a sitation where you can unload the kittens if it doesn't work out.