Spousal benefit with reduced old age benefit

[StevenK11041]

I have a question I am having trouble getting a clear answer to.  I'm sure it has been asked since it should be a common issue, so forgive me for repeating.  But even the person at Social Security sounded uncertain.

Assume my wife and I both turn 62 in January.  My estimated PIA is $3200, hers is $1300.  We are both fully qualified, have been married 35 years, have no children under 25 and have no disabilities.  And assume we each work the amount SSI uses in their calculations until the day we apply for benefits and then stop working.

If she applies at 62 and gets a reduced old age benefit ($900), and then I apply at 70 and get my old age benefit plus 24% ($3900), she should start to draw spousal benefits when I start drawing.  She will also be 70.  How much will her benefit be at that point?  Will her benefit continue to be reduced by the $400 it is reduced due to retiring before her FRA or will the calculation be reset based on her becoming eligible for spousal benefit past her FRA?

Second question.  If she gets the full spousal benefit (1/2 my PIA), $1600, and I am getting the plussed-up old age benefit ($3900) then together we are getting more that my "Maximum Benefit" of $5400 (from my annual statement).  We either of our benefits be reduced because of that or is the part that she earned from her old age deducted from the total?

Thank you very much for any answers and please include how confident you are in your answer.  I have read and reread 42 USC 402(q) and it all comes down to what they mean by "month".  The month first applied for retirement, or the month entitled for spousal benefit, since I assume she is deemed to file for that at 62, when she applies for her own benefit.  So if you have a reference or clarification from a Social Security publication, please include it.