1. She turns 21 in June.

2. She is turning 21 in June.
[Which one is right?]

Both are correct, but #1 is much more commonly used.

1. She turns 21 in June.

2. She is turning 21 in June.
3. She will turn 21 in June.
[Thank you. Does #1 and #2 mean #3?]

Both sentences are grammatically correct, but they have slightly different meanings.

1. "She turns 21 in June" indicates the fact that her 21st birthday falls in the month of June. This sentence suggests that her birthday will occur in June, but it does not specify when in June.

2. "She is turning 21 in June" also indicates that her 21st birthday falls in June, but it implies that it is an upcoming event. This sentence suggests that her birthday is approaching in June.

So, the choice depends on the context and the intended meaning.