Good for you! One of the best ways to battle kids' sense of entitlement and greed is to get involved!
"Less fortunate" doesn't have to mean "poor" - look at senior living centers and nursing homes that would love to have people come in and puzzles, make seasonal decorations out of construction paper, take a walk around the grounds pushing a wheelchair, join in sing-a-longs, etc. Many of these folks have no family or no family close by, and even if they do have someone, they need mental stimulation and entertainment. The staff can screen out those who are so medically or mentally compromised that it would be distressing to your daughter and help you work with higher functioning folks who would love to have a surrogate grandchild!
Look also for centers that help new immigrants - I know there is one in Worcester (too far from you but maybe there is something closer). Many of these places have a food pantry, but also a clothing "pantry", a housewares & toys "pantry", and collection centers for other essentials for people who have come to this country with very little. As they escape poverty, gangs, violence or political unrest, they sell everything they have to afford passage. They may come from warm climates and didn't have warm clothing to begin with. Helping to straighten or sort incoming items, perhaps welcoming customers, sorting toys & their parts, stacking pots & pans in sets, all would be helpful and age-apprpriate activities for a 7 year old.
Another organization you could check out is the Interfaith Hospitality Network. This is usually coordinated by or done in association with a local homelessness & housing agency, or at least you can find the IHN in your area through any housing group. IHN is a coalition of churches and synagogues that take turns hosting homeless families until they can find housing. Usually families go to one house of worship for 2 weeks (with cots and room dividers brought in to give some privacy unless there are individual rooms such as classrooms that can be allocated), and then there is a shuttle van that takes them to the local Y for showers, then takes the kids to school. Remember that homeless kids don't have a "neighborhood" so they don't have pals other than in school. I've volunteered at my synagogue many times - jobs include making box lunches for kids to take to school, playing with visiting children to give them some fun and give the parents a break, keeping them company during dinner, preparing and heating and cleaning up after a group dinner, entertaining a baby so the parents can do something else, helping with homework, joining the group to watch a DVD, etc. We've always used kids of all ages for different things - you sign up for the shift and task(s) that you want. As families find housing, they rotate out and new families rotate in. Al families are highly screened with no red flags or problems. What we found with all the participating kids is that they learned "homeless kids are just like us" and "I'm pretty lucky that I have a home and toys and parents so maybe I shouldn't complain so much about what I DON'T have."
You could also set a goal of a monthly batch of cookies or an apple pie to take to the firefighters and police officers who work holidays and overnight shifts. They aren't exactly "people in need" but they are woefully under appreciated.
I've also seen kids on occasion at the Red Cross blood donation center, just giving donors their clipboard with reading materials/instructions or waiting on the finished donors in the canteen where they have to wait a half hour. I've seen kids (with a parent supervisor) serving the drinks and cookies, writing the departure time on the napkin provided, picking up the wrappers and empty cans for recycling, and handing out whatever giveaways some company has donated (t-shirts, coupons, etc.). It's a way for kids to see there is something vital and lifesaving that good people donate regularly, and to make them less afraid in medical situations.
What I like about all of these is that kids can donate all year round. Yes, toy drives at Christmas are fine - but everyone does that, and then all these needy people are sitting around all year with no one thinking of them! There's also little or no connection with the recipients of the services so it doesn't always make a solid impression on the volunteer children.
Good luck. Hope these help.