If my wife starts drawing on her social security now (about $1300/month) can she still get a spousal benefit when I start drawing at age 70 (about $3400/month). 50% of my draw will be higher then hers.
Maybe, but only if 50% of your primary insurance amount (PIA) is higher than your wife's own PIA. A person's PIA is equal to the amount that they'd receive based on their own work record if they started drawing at full retirement age (FRA).
For example, say that your PIA is $2600 and your FRA is age 66. In that case if you waited until age 70 to start drawing you could receive a retirement benefit rate of $3432 (i.e. $2600 x 1.32), however, your wife's spousal benefit rate would still be computed based on 50% your PIA of $2600. And, if she's already drawing her own Social Security benefits her PIA would be subtracted from that 50% in order to determine whether or not she qualifies for an additional spousal benefit. So, if your PIA was $2600 and your wife's PIA is at least $1300 and she's already drawing on her own record, she wouldn't be eligible for any additional spousal benefits when you start drawing.
It sounds like you and your wife a number of different filing options available to you, so you should strongly consider using our software to fully explore and compare your options so that you can choose the best possible filing strategy.