If a public school district doesn't want to have a Christmas charity drive and a parent is really concerned, then why send their children to public school? Send children to Christian community schools, where members of a church voluntarily donate their money to maintain it or whatever school happens to be the interest of the individual.
As for Christmas; Christians don't care if people recognize Christmas. Foremost because Christians are educated and know (Read the bible) that the birth of Christ wasn't in December, it was in September.
Christmas is fun and Christians are free to enjoy such events, but Christians don't get upset about this kind of garbage.
This goes for all holidays, no date should be determined by the State for any individual or collective group. Otherwise the State will want to regulate Easter, when Christians who read the bible know that Christ was crucified on Wednesday and rose on Saturday, not Friday rising on Sunday.