I had this surgery. The first one involved the tendon release and tendon transfer when I was thirteen years old. The other foot was done a little over one year later. I wish to God I could've had this surgery when I was your daughter's age! Because I was a toe walker for so long, my toes were permanently clawed and I had to have surgery to remove their joints and fuse them in later years. In this short post I can't really convey how difficult it was to grow up with those foot deformities. I did have an excellent recovery when I was a teenager, but I really missed out on being a kid during those pre-teen years because it was so difficult to get around.
My advice is that you speak to the surgeon about pain management. Make certain that s/he will take pain management seriously - even considering how young your daughter is. (Since those first two operations, I've had at least a dozen major foot surgeries - the most recent was two weeks ago. The BEST thing I've found is when the surgeon shoots the foot full of a local anesthetic immediately after completing the surgery. The foot is completely numb for MANY hours after you wake up and I cannot tell you how important this is for the healing process. My third surgeon's philosophy was NO pain for the first 24 hours - and this cut the recovery time by 2/3rds.) Talk to the surgeon about what exactly will be done to manage your daughter's discomfort.
The tendon release is REALLY easy. It only involves soft tissue - so it's really not painful. The worst thing about dealing with the Achilles tendons is that you have to protect them while they're healing . . . which is why she'll be in the casts for six weeks. (When you get older, it's an eight week recovery period!)
My tendon transfer was the most painful procedure - mostly because my surgeon wasn't concerned with pain management for children. (This was back in the 80s, so it was before pain control became a priority. Things have really improved over the last twenty years on this note.) Anyway, my tendon transfer meant that they had to drill a hole through my foot in order to attach the tendon to the new location. With proper pain management (which I most definitely had during subsequent operations, the recovery was easy.)
You don't say what the underlying reason for the surgery is, so I'll tell you what I usually experienced after surgery. I was groggy and grumpy after waking up. I really wanted my mother nearby - even though I was grumpy at her. I was always very thirsty and hungry, but the darn hospital staff would keep me restricted to liquids for the first several hours. (I got to the point where I'd sneak food in to the hospital because I never had a problem with nausea, but many people are queasy after surgery.) Honestly, my biggest post-op problem is that they never padded the casts with enough dressing - except for the heel cord procedures!
The younger you are, the quicker you bounce back. She will recover from this in record time and will be raring to go. She won't remember this operation. It's a simple and easy procedure and I can tell you from personal experience the results are AMAZING!
I'm sorry this is as long as it is. I know you wish you could have the surgery on behalf of your daughter, but I have to tell you that I am excited for her. This surgery will have an amazing pay off. The pain is virtually nothing compared to that - and the pain is only on the radar for the first 72 hours when you're an adult. (Again, I had tendon and bone work done two weeks ago so I really know my stuff here!) At the age of two, her healing process will be faster than that! I'd give her two days before she's raring to go.
Please don't hesitate to shoot me a private message if there is any information I can give you.