I think she might get dressed up nice, if she was wanting to convince him to take part in their having a baby. She may have hoped that his feelings about becoming a father would be triggered in a positive way?
I really wish that ALL young pregnant women, would be extremely cautious in 'meeting up with' the birth fathers, when circumstances are so rocky. How many cases have we seen here, where hopeful pregnant young ladies, go off alone to have that 'talk' with the sperm donors....never to be seen again?