My wife began collecting a spousal benefit when we turned 66 (based on my earnings-I filed and suspended). Can we, before age 70, have her begin to collect "her" Social Security and have me get a spousal benefit based her Social Security and then file for my own benefit when I turn 70?
Once you file on your own record, whether or not you suspend benefits, that becomes your primary benefit. From then on, you can only receive an excess benefit on someone else's record. So, if your wife's full retirement age benefit (PIA) is more than double the amount of your PIA, you could potentially receive an excess spousal benefit on her account when she files on her record. However, your wife would then stop drawing spousal benefits on your account, and she would no longer accrue delayed retirement credits.
Based on the limited information in your question, you are probably following the best plan possible. You should likely keep the status quo until you each turn age 70, and which point you will start drawing your maximum possible benefit, and your wife can file on her own account. As I'm sure you know, however, the best strategy depends on numerous variables, so you may wish to consider running the maximization software available on this website in order to make sure.