I think it's a wonderful idea to get another kitten. Based on my personal experience, Ragdolls love company and mine just hate being left alone.
When I got my first Ragdoll Cody, I already had two rescue females and they accepted him into the family pretty quickly and my one girl, Mittens in particular was the motherly type and took him under her wing, so they all 3 got on together and he had company if I wasn't at home.
Then I decided to get another male Ragdoll kitten in 2014 and Fozzy came home in the June and a month later I got his littermate sister, Katy.
They seemed to remember each other and were totally bonded, and it was such fun having two kittens, I wish I could do the same this time around but I can't.
This was Fozzy and Katy not long after Katy came home...both bluepoint bicolour.
They remained very bonded till I unfortunately lost Fozzy to FIP last November at 5,5 years old.
As to personalities and choosing between a male/female...
Here I can only share my personal experiences. Whether male or female I've found ALL my cats to be very affectionate and loving. They've all wanted my attention and even today, Cody and Katy vie for my attention. I couldn't tell you who is more affectionate, they both are in their own different ways. Cody will scream at you if you don't pet him and will come purring like an engine making biscuits and giving you headbutts.
Katy will throw herself at your feet and roll over purring and making biscuits in the air or come up and rub herself on you.
So both, very affectionate and extremely loving.
If there are differences, then the females seem to be more playful, males lazier.
Fozzy was a real mommy's boy and would follow me almost everywhere and sleep on my pillow at night. Katy prefers my legs.
And then there's the size.
Fosco aka Fozzy at you see was bigger than Katy, to give you a clue, Katy is a decent size for a female, she weighs about 14lbs, her brother was around 21lbs.
Wishing you all the best with your little girl, she seems to be making good progress, and if you do choose to get another kitten please keep us updated. I think you won't be sorry.