She’s fortunate to have a friend that is concerned about her. Sometimes you’ll see couples who belong to the same socioeconomic class really struggle with their relationship. There are many factors that make two individuals compatible with one another. If she has interacted many times with her in-laws…and gets a good vibe from them…and if her parents have checked out the guy and his family and are comfortable with them and trust them…then InshaAllah things will be okay. Ups and downs are a part of every relationship…and she’ll have to deal with them…regardless of who she marries. Just be supportive and celebrate her happiness with her.