Whether your sister is younger, older -- or even the same age -- as you, spotting the signs of a crush can help you to better understand what she is going through. From interpreting her actions and reading the unspoken signals to truly listening to what she is saying, knowing when your sister has a crush on a boy isn't a constant challenge if you know what to look for.

The Main Attraction

Although all romances during the teen and young adult years may seem like love, without closeness and commitment you have more of an attraction than a real relationship, according to the TeensHealth website. When your sister develops a first crush it's likely that she'll have a major attraction to the boy who's in her eye. Listen to what she's saying and you're likely to hear gushing exclamations such as, "He's so hot" or, "He's the cutest boy in the school."

Suddenly Shy

A first crush may throw a teen or young adult off balance, making her feel emotions that she's never experienced. Instead of feeling completely comfortable around the boys in her grade, your sister may suddenly start acting shy around one specific guy. When your formerly talkative teen sibling clams up around a certain someone or can't look a particular boy in the eyes during a social situation, her lack of words may signal that she's crushing on the guy.

Mrs. Crush 4-Ever

Take a look at the doodles that your daydreaming sister is scribbling on her notebooks or across a blank piece of paper. If her usual rainbows and unicorns are now swirling letters that read her name plus a boy's name or "Mrs." and the name of a boy, it's likely that the dude from her doodles is also her crush. While it's not acceptable to snoop or sneak through your sister's personal belongings to look for these scribbles, if she leaves them out in plain view or shows you, take it as a sign that she's got a crush.

Chatty Cathy

Is your sister non-stop talking about one specific boy? If so, it's a major sign that she has a crush. While some young people are embarrassed to tell anyone, even a family member, about their crushes, others are so vocal that it makes their attraction incredibly apparent. Your sister may not come out and say that she has a crush on a specific boy, but she may constantly gab about what he wore to school, how well he did in the school play or what the other girls are saying about him.