True. Although most fics also see her as seeing herself as left behind (woah convoluted sentence).

But it's an interesting omission from canon, I think--Lucy's friend is mentioned but betrays her in VDT; Jill and Eustace don't seem to have other friends; Susan's (implied) friends are implied to be Bad Sorts. They never seem to miss other people or have relationships with other people. And I think it cuts both ways: their time in Narnia would lead them to be very social, but it might also mean they tried to stick to people who understood.