I'm not a native English speaker.
We were supposed to use the verb be instead of the verb belong using possessive pronouns.

The question is

• Do those toys belong to her?

The answer given by some is

• Do those toys are hers?

Isn't it simpler to say:

• Are those toys hers?

Sorry for bringing a confusing issue and not stating it properly.
Thanks a lot. I appreciate your concern very much. I enjoy learning English.