An 18 year old entering the country with the intent of staying longer than a few weeks alone will raise eyebrows at the border. Next question will be regarding

An 18 year old entering the country with the intent of staying longer than a few weeks alone will raise eyebrows at the border. Next question will be regarding available funds. How can she afford to travel that long? Staying "with friends" is also suspicious, especially when she hasn't met them in person before.