Answer:
She has $68 dollars remaining
Explanation:
(no bar diagram needed, lol jk.) 
anyways she started off with 153, right? 
She then buys a bike worth $105; thats -$105 which leaves here with $48 dollars
Then ooo its her lucky day, she finds a $20 dollar bill, you add it to $48 (+$20) , now she has $68 dollars in total. 
<3