I'm not going to chastise you for this decision. You are well enough aware of the nature of this procedure. I will say, see if you can find a vet who does the procedure with the laser. There is less chance of hemmorrage and a much quicker recovery time. The last cat my mother had declawed was done this way and it was a lot easier to care for him afterwards. The prior cat had a lot of hemorraging afterwards and as a result of the turniquets has nerve damage in one foot. Since then though, claw removal has changed, and most vets use the laser to zap the nail bed, instead of rip out the claws.
Aftercare is simple, no jumping! Keep the cat as mellow as possible. She will be lethargic the first day as the anethesia wears off, but she will get more active. Keep the litter box impeccably clean, clean it as often as possible and change the litter completely before she comes home. If there is another cat in the house I would even go so far as to buy a disposable litter pan and seperate the cats for the first few days to prevent infection. Look for signs of infection, ie: hot swollen paw pads, or bad reactions to the anethesia like vomiting, and not eating or drinking. Otherwise, your vet will give you advise on after care. Lots of cuddles and treats and a comfy warm bed god far in aiding in recovery!
After recovery, leave the scratching posts and stuff out, my boy with no claws still rubs his feet on them cos they have scent glands there!
My only request is this, ONLY do the front claws. Leave the back claws for defense. All of the cats we've ever declawed kept their back claws with no problems, and all of them used them at one time or another with either another cat or dog! There is never a good reason to 4 paw declaw.
It is obvious that this is a decision that you have considered thoroughly, and that you have weighed the benefits and cons. Personally I see no good reason to rehome a 7 year old cat, just over declawing. If the soft claws don't work (most people I know have had little success with them and many vets I know scoff at their very idea), declawing does not make you the worst mother ever!
BTW: just so I don't get chastized, I am against declawing, but if someone is going to do it, I hope that they do it after being well informed and having no other options. I can't and won't pass judgement.