Yes, you can ride a horse that has foundered. And certainly if she has not relapsed in ten years, your prognosis is good, but I wonder what she has been doing for the last ten years. If she has been off of grain and not ridden, then might want to take it easy to begin with.
I'd recommend pairing yourself up with a good farrier and constantly monitoring her condition. Also, horses that have foundered in the past can be more susceptible to other conditions, such as bruising.
As long as you are aware of her condition and care for her accordingly, I see no reason why she can't become a valued riding companion.
Best of luck :)