"Forest Pansy" redbud - however, some contend there are pest issues here;

Serviceberry

"Prairie Fire" crabapple

What color is her house? Honestly.

I like Forest Pansy Redbud but it is brittle and susceptible to branch breakage. It is as beautiful an ornamental tree that you'll find.

If the house isn't white, I'd also suggest Styrax Japonica (Japanese Snowbell) which is very durable and flowers in June.

Either way, a very nice thought of you to buy a tree as a housewarming gift.

How about a japanese maple? There are many different cultivars and depending on the variety it could have 4 season interest. There are variegated leaf types, colored bark, lace leaf dissected types, mounded or upright, green or red leafed types etc. They usually are small trees but some can grow to 15' plus but some are dwarfs growing to no more than 3' tall. Do a google search on japanese maples-some of the online nurseries have very good photos and description of the different trees. Good luck.

Hey Janice here are a couple of ideas for your tree. Try Oxydendrum arboretum - Sourwood tree or Lagerstroemia indica - Crepe Myrtle or my favorite Franklinia altahama- Franklinia tree. Or see what your friend might like & send a gift check, or call the local nursery & have it delivered.
Hope this helps. Frank

I'd be leery of planting a Franklinia Altmaha on an exposed hillside in Hunterdon Co.( and more than likely it is an exposed property). They're extremely 'prone' to winter wind damage. Remember, this is a tree that was found in Georgia. Zone 6 is a "reach" in my estimation.

My specimen of 6 years is in a very favored southwest exposure and is protected from the north & east with a stockade fence. The other one that I've planted in Colts Neck has similar exposure and attendant protection.

They're extremely 'slow growers'. I think that the poster can do far better with a larger specimen that the owner would appreciate over time.