F1 to F2

[manskinu]

my sister is traveling to US on F1 visa but she doesnt plan on studying here. Actually her husband is here on F1 and she wanted to come here but was denied a visit visa. Now she is traveling on F1 as that got approved. My question to you is 'Does she really need to pay admission to a university here and take a semester or once she gets here, she can get transferred to F2? (spouse of her F1 husband)??'

awaiting a quick reply