The only
Allie people I know are either
Alison or
Allison. I'd use
Alison, but DH can't for family reasons; I'd happily use
Alice but I wouldn't expect it to have any nn. The
Alexandra people I know are known as
Alex or
Alexa; one I think was
Lexie.
Allie is very young-sounding. I can't imagine an
Allie older than, say, eleven.