Since you are in the US for more than 5 years, you would be a resident alien if you meet the substantial presence test.
As a resident alien with a nonresident alien spouse you have two options:
1. File married filing separately. Your spouse would need to only file form 8843 if she had no income if she had income, form 1040NR plus 8843.
2. Add a statement that you both choose to treat the nonresident alien spouse as a resident alien for the entire year. You can then file jointly, but your spouse would have to declare worldwide income for the entire year.
If your spouse has no ITIN/SSN, you would need to apply for one if you file jointly. If she is not eligible for an SSN, you would need to apply for an ITIN with the return.
I am not sure about the child, as you cannot claim nonresident aliens as dependents and the choice for the spouse cannot be made for the child. I will try to get a clear answer to this.
