I think it is tough on older cats when owners take in new animals. Especially if the cat only "tolerated" her other "brothers." You have 4 - 6 years left with your calico, you want them to be the best years for her.

I have found male cats to harrass my older or sick females every time, and have vowed never to bring a cat into a geriatric cat's life, or a male cat into a female's life.

Just my experience.

Of all of the cats I've fostered, my older ones seem to get along with the kittens best it seems. However, I've had a house full of adults (seven total)and after about a month or more time, they became stablilized with each other. They figured out who to mess with and who not. There was a couple of separation time outs but (nock on wood) nobody drew blood. I haven't really noticed a big difference in the sexs but it does seem the females do not always put up with the silliness as often from the males. They seem to dominate the "herds". When I introduce a new freind(s), they are quaritined in a separate room for 1-2 weeks. Gives them time to settle and the others time to quess who is on the other side of the door. Then I open the door for very short periods and step back. Hissing, snarling, and paw biffing is OK. No actual fights allowed. Gradually they walk out on their own to explore. Do not leave them alone with your cat for about a month or two. This helps prevent any altercations while you may be gone. I've had some that just are not comfortable around others and they find thier spot away from everyone. If you do decide to get another (or two), you'll just have to give it a try but be very patient. Good luck!

Good advice from the previous poster...I don't think anyone can really predict how cats/kittens will react...We brought in 2 little girls and 1 of our older males will not get along with 1 of them and we have no idea why...She wants so bad to be friends and he'll give her a swat or hiss if she gets too close...He has always been the one that got the most attention, so that's not the problem....
I think it's great you wanting to adopt 2 fur babies and it will just take time and patience...Just make sure your older cat doesn't feel neglected.....Good luck!

I adopted two 1 year old siblings when my old cat was 16. As the posters above say, it is hard to predict what will happen and will require patience, but I say go for it! My old lady cat was outraged at the newcomers for a long time but slowly became tolerant. I gave her lots of extra love and made sure the newcomers were to be respectful around her. After about a year, they were grooming each other and sleeping together (occasionally). Interestingly, the old lady warmed up a lot more to the male cat than she ever did to the female. Although it was tough going at first, I never regretted my decision to bring two new rescues home. Old lady Elaine passed away last year at the age of 20, and I now have two wonderful 5 year olds.

Thanks elly_nj, pmkgerol,irishdancersgram and marita. I realize that this is not going to be easy on my calico. I an extremely patient, and I am home most of the time (although I spend much time in the garden). I have delayed my decision.. just for a few days. However, I would not want to wait too long as she may get used to being the only cat. I truly think she is lonely--I think she might even miss her brothers!
After about a year, they were grooming each other and sleeping together (occasionally).
That would be worth all the wait, Marita.. They all sleep huddled together at the shelter, and I would love to see that at home!!
Thanks everyone, Anne-Marie

May I just add that my males stalked my females and made their lives miserable for their entire lives? I had to separate them when I left the house. When little Keesa got cancer, it got really bad, and Finney harassed her even more.

Good luck.