Translation:This vacation home, someone gave it to us.
...this holiday home, we were given it' ... comprehensible, but normal english word order is subject, predicate (verb ) , direct object, indirect object.
or, "somebody gave this holiday (vacation ) home to us . "
so, "we were given this holiday (vacation ) home " . . .
"someone " (in this sentence ) is "on " . . .
Only donnée is correct. If the direct object appears before the verb then the participle in avoir agrees; otherwise it doesn't:
J'ai perdu la robe que tu m'as donnée. Perdu doesn't agree since the object comes after the verb, but donnée does because la robe and que come before it.
Les enfants que nous avons vus ne sont plus là.
J'ai acheté une robe. (no agreement)
Je l'ai vue. (I saw her. This agrees with the elided la. The pronoun might also be translated as "it" if it was a house or goat or something else feminine.) Je l'ai vu (masculine). Je les ai vus (masculine). Je les ai vues (feminine).
French grammar is weird, especially given that oftentimes these differences don't change the sound in the least.