Acer Aspire 5745G ReviewAcer Aspire TimelineX 4820TG Review
Both get decent reviews for a mid-range budget laptop. Slight edge to the 4820TG.
The 5745G has a dedicated numberpad while the 4820TG does not. It could come down to the features like that. Is a number pad important to her work? I'd have a hard time working on a laptop without one.
Everything else being equal, unless a long battery life is especially important to her work, I think you can let her read those online reviews and pick the one she favors.
(gets you off the hook, you see)