Contribution to spouse's Roth IRA

[PT48]

I'm in my 70's, still working (receive a W-2), and contribute the maximum allowed to my workplace 401(k).  Can I still contribute to my spouse's Roth IRA although she has no earned income?

[MinhT1]

Yes. 

If you have earned income, you can contribute to a spousal Roth IRA for your spouse, up to $6,500 ($7,500 if she is 50 or older).

Your joint modified AGI must be less than $218,000. Between $228,000 and $228,000 you can contribute a reduced amount.

[Opus 17]

Yes, but only up to the amount of your compensation.  For example, suppose you work part-time and earned $10,000.  If you contribute $7500 to your IRA, you can only contribute $2500 to your spouse's IRA.