Shyness

Off hand, I'd say her problem is shyness.

I like him all the better for his shyness.

His shyness made public speaking a torment to him.

I like her all the better for her shyness.

I finally overcame my shyness and asked him out on a date.

Shyness first shows itself at school.

Tom finally overcame his shyness and asked Mary to go out with him.

Her shyness makes me like her even more.

Shyness doesn't seem to be one of your problems.

I have tried to overcome my shyness, but to no avail.