Congratulations on your new addition. It sounds as though
you're off to a great start. Patience will be the key to
winning Boo over. If you can already pet her feet and chest
that's definately a good sign. Just keep that up a couple
times a day and offer her a spray of millet right outside her
reach so she has to get on your hand to eat it. Make sure she
knows what the millet is first so it doesn't scare her. Once
she knows what it is and decides she likes it (budgies love
millet) then only give it to her when she is on your hand or
out of the cage with you. That will make her associate being
with you as a good thing. Talk softly and be patient and it
will all work out!
Below is one of my favorite budgie sites. It doesn't list
anything on training, but if you want to find out what sex and
color mutation you have then check it out!