Is there any merit of making charity on the name of ancestors to us?
We often do charity on our name that for sure directly gives us merit.
But Is there any merit to us if we do charity on the name of our ancestors?
I am slightly confused as regards what exactly you are asking but the charities that are made during the Shraddha rituals are the ones made in the names of the ancestors. And, such charities are considered as highly meritorious.
As fire exists in all [pieces of] wood [in an invisible form but is manifested] by friction, so virtue is, forsooth, visible by gifts made at a S'raddha. (356)
To make gifts at a S'raddha is undoubtedly equal to the understanding of the meaning of all the scriptures, bathing at the sacred places and the fruit of all the scriptures. (357)
Atri Smriti verses.
And some more verses from the same Smriti:
Of all gifts, that made at a S'raddha is superior.
The gift [made] at a S'raddha is [the instrument of] purification, when sin equal to [the Mount] Meru [in height] is committed.