Dan and Jazz are correct. The word "wondering" is not a common adjective. It is the present participle of the verb "wonder." It is used in continuous tenses. I'm wondering if you could help me. I was wondering when she would find out that she'd been promoted! When it is used as an adjective, it is used in expressions like 'a wondering look" (meaning puzzled or curious)

"The soup smells wonderful." "Wonderful" is an adjective, with a meaning that is only loosely connected to the verb "to wonder." "Wonderful" means good, very good. Literally it means so good that it is outside the range of normal experience, and evokes a sense of awe or wonder. "Wondering" is a present participle and doesn't work like an adjective. And it usually has the meaning of thinking about something that might or might not be true. You can't say something smells "wondering." You could say "That soup smells so wonderful, I am wondering what ingredients are in it."

The soup smells wonderful.

The soup smells wonderful

Smell wonderful is the correct way to express your kindness