I was at school with three young Alices, all cousins! One went by
Alice; when one of the others discovered that she was not alone, she gave up being
Alice and called herself
Arline instead; and the third one used her middle name which, remarkably, is Marsephine. (In fact, they all had the same mn, no doubt for sound family reasons.)
It suited them just fine, I thought. There were more
Alison people than
Alice people around, back then, but it didn't matter at all.
I've only met two adult Alices. One was married to my mother's cousin, and seemed pleasant but I hardly ever saw them. The other was a receptionist/telephonist at a foreign embassy - a South African of Lebanese descent - and therefore had to be charming, and was.
I'd use
Alice for a child without hesitation. In the absence of a suitable child, I used it for a cat with great success; she was known informally as
Alice the Alley-Cat and was a very pretty animal.