Nothing wrong with a little skeptism because there are a lot of people on the Internet putting out false information and its hard to know who you are really talking to.
There are the obvious safety hazards with meeting up with people online, and although it can be done you have to be smart about it.
Some of my friends are so eager to be in a relationship they have tried online dating. I think sometimes people are a bit too trusting, you can't take every thing at face value right off the bat, and people should be realistic about their online relationships. Falling in love or calling someone your boyfriend when you hardly know them or have never met face to face is unrealistic. There are a lot of vulnerable and dare I say slightly desperate people out there who may be easy to take advantage of due to their open hearts, eagerness and gullibility. Women need to stay alert set the terms and be aware.
I don't think there is anything wrong with meeting people online we do live in a technologically savy world and sometimes it works out. my cousin married someone she met online and it worked out and one of my other friends has been through a divorce because her husband was cheating on her with various women he met on a popular dating site. Like anything it can be good or bad. It can be a great way to meet a variety of different people easily at the click of a mouse or it can be destructive. I don't think you are wrong to be worried about her just remind her to be safe and take proper percautions.