My spouse had an internship during February 2017 until April 2017.?
You can correct your W4 allowances by contacting your employer. If you dont know who to contact (probably HR) just talk to your boss. You will need to fill out a new W4 form and potentially update your settings in an internal HR application. You cannot retroactively update your W4 allowances, so nothing can be done about 2017 at this time (late Jan 2018). If it helps, you can generally owe up to $1000 in federal taxes without penalty (and there are other rules where you can avoid penalties for higher amounts).