I recommend the Infinity in a 51 or 54... The Lotus isn't exactly a soft board and if her current board is to stiff, eh.
Should maybe feel the flex on her current stick then go to a shop and press the Lotus and Infinity to see if there's a significant difference.
"When I do good, I feel good; when I do bad, I feel bad. Thatís my religion." - Abraham Lincoln
Moral of the story: If your going to rob people, wear a diaper.