You have the option to file as Married Filing Jointly or Married Filing Separately. If you don't file jointly, you will miss out on many deductions and credits. That said, if that is the only income she has, she wouldn't have to file unless you live in a community property state.
If you live in a community property state, you both have split each other's income and expenses on your own tax returns. In that case, she will need to file. Community Property states are: Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin
Is it better for a married couple to file jointly or separately?
Married Filing Separately in a Community Property State