I will begin drawing my social security Jan, 2017 when I am 70, so I maximized that. My wife is 6 years younger so will not be full retirement age until Jan, 2019. at which time I know she can draw a spousal benefit of 1/2 my what my benefit was at age 66. My question is this - is there a limit to the total amount we can draw from my primary and her spousal benefit? It seems I have heard that there is a maximum of $4500. It so my + her spousal would exceed that so it might be beneficial for her to go ahead and get spousal benefits earlier since she would not be able to get the 50% anyway. Also if she did file before age 66, would that eventually decrease any widow's benefit?
There is a maximum family benefit, but you needn't worry about it. The delayed retirement credits (DRC) you will earn by waiting until age 70 to start drawing do not count toward the family maximum. Only your full retirement age rate and your wife's full spousal rate will count toward the family maximum, and the family maximum payable on your record will be high enough to cover that amount.
The family maximum benefit on a retirement account is never less than 150% of the worker's primary insurance amount (PIA). The PIA is essentially the equivalent of a person's full retirement age benefit rate. Therefore, if only the retired worker and their spouse are drawing benefits on a record, the family maximum would never cause a reduction in their benefits.
Regarding your other question, even if your wife files for a reduced spousal benefit before her full retirement age (FRA), she will receive an unreduced widow's benefit if you die first and she is FRA or older at the time of your death. Her unreduced widow's benefit would be 100% of your full rate, inclusive of the DRCs you'll earn by waiting until age 70 to start drawing benefits.