You should be able to claim her as a dependent on your 2021 tax return under the Qualifying Child rules providing she meets all the requirements.
To be a Qualifying Child -
1. The child must be your son, daughter, stepchild, foster child, brother, sister, half brother, half sister, stepbrother, stepsister, or a descendant of any of them.
2. The child must be (a) under age 19 at the end of the year, (b) under age 24 at the end of the year and a full-time student or (c) any age and permanently and totally disabled.
3. The child must have lived with you for more than half of the year. Temporary absences while away at college are considered living with you.
4. The child must not have provided more than half of his or her own support for the year.
5. If the child meets the rules to be a qualifying child of more than one person, you must be the person entitled to claim the child as a qualifying child.
6. The child must be a U.S. citizen or U.S., Canada or Mexico resident for some portion of the year.
7. The child must be younger than you unless disabled.
If she is in the military can she be claimed as my dependent is the question?
@mswandaad wrote:
If she is in the military can she be claimed as my dependent is the question?
Yes, she can be claimed as a dependent in 2021 if she was under the age of 24, a full time student in 2021 and you provided over one-half of her support in 2021 even if she is active military in 2021. The Qualifying Child rules prevail if she meets all the requirements.
For tax year 2022 she could not be claimed as a dependent if she remains active military in 2022.
Is there a cap as to how much she can earn and still be considered a dependent?
@mswandaad wrote:
Is there a cap as to how much she can earn and still be considered a dependent?
Under the Qualifying Child rules there is no income requirement but there is the rule that you had to provide over one-half of her support for the year. If she joined the military in July then you probably provided over one-half of her support for the year.