Should she really do this?

so my cousin is this really sweet girl but shes kinda gullible. she said that a guy that she IMs is in a relationship with her but they r long distance and haven't met in person but i guess they are in love.and theyve seen each others pics and everything. i don't know if the guy is being real with her, cuz not gonna lie there r some smooth talkers out there.but he is talking about going to see her. well she said they have been talking for awhile and they txt so much that they only get about 5 hours of sleep and he would apologize for next replying for two hours. when i was talking to her today she said its been 2 days sense they last talked and he wont txt her back and hasnt emailed her but when i added him on yahoo he talked to me for alittle bit, he doesnt know im brookes cousin yet. but should she go out with a guy that lives 7 hours away and might flirt with other girls on the computer? i have no clue what to do