Hello, my name is***** and I have over 20 years of experience as a veterinarian. I'm sorry to hear that your pup ate something she should not have, 2 diet pills.
There are lots of diet pills, but many contain amphetamines and caffeine, both of which dogs tolerate poorly. Since she just ate them, it's worth trying to get her to vomit them back up.
You can give her 1 tablespoon of 3% hydrogen peroxide per 10 pounds of body weight mixed with bread chunks or ice cream (no more than 3 tablespoons even though she weighs more than 35 pounds).
Then take her outside and run her around to get the peroxide bubbling so she vomits.
If no vomiting in 10 minutes repeat the peroxide dose once.
If she vomits and seems to clear her stomach and be done I would check to see if the pill pieces are present.
Once she finishes vomiting and empties her stomach to try and settle her stomach today you can give either:
1) Pepcid-ac (famotidine) at a dose of one half of a 10mg tablet per 10 to 20 pounds of body weight every 12 hours.
2) Prilosec (omeprazole) at a dose of one half of a 10mg tablet per 10 to 20 pounds of body weight every 24 hours.
These will reduce stomach acid and should help settle her stomach.
If you have the ingredient list I will be happy to take a look, but in the meantime I would get her to vomit.