Marriage

My best friend just got into a relationship and has been dating a 19 year old (just turned 19 in July)for maybe close to 4 months. She is 21 years old. She wants to get married next July 2019. She was in a two year relationship before they dated with my brother in law and that didn’t end well so I think she’s rushing this relationship he just started college and I don’t think it’s the right time for them. I want to be supportive but at the same time idk.... help??? Any thoughts? I know it’s there lives and they can do whatever they want but they haven’t even lived together or even in the same town??