Both these medicines contain cyproheptadine
as the active ingredient- which is an anti-histamine
The appetite stimulation happens as one of the side effects of the drug.
It can result in other unnecessary problems like dry nose, dry mouth
Its better to avoid such appetite stimulants.
9 kg at 11 months is okay and not to be worried too much.
Give her lot of home made foods in various forms, shapes and colors- make eating time interesting- make it a game- involve her in each step of food preparation- encourage her to self feed.
Give her fresh fruits, vegetables, nuts, egg etc. Limit milk to 2 to 3 times a day.
Ask your doctor for micro-nutrient supplements- as hidden micro-nutrient deficiencies can present with low appetite.
Hope I have answered your query.
Wish your daughter good health.