In the meantime, I can give you some general direction as to which foods are okay and which you should avoid. Of course, a lot of what your wife can and cannot tolerate will be based on her own personal experience. For example, apples are generally considered an acidic fruit, yet some varieties are much more acidic than others. She may be able to eat a Golden Delicious, but a Granny Smith will need to be avoided. The same is true for many fruit varieties.
All plant tissues are acidic to some degree, and some are much more so than others.
As a fruit or vegetable ripens, its acidity decreases, which is one big reason why immature fruits are sour and ripe ones are sweeter. Therefore, your wife should eat fruits and vegetables as ripe as possible. Almost all fruits are considered to be acidic. The concentration of acid is lower in vegetables than it is in fruits. Tomatoes are the vegetables with the highest concentration of acid with a pH of 4.0 to 4.6.