My 2¢ -
1. YES, about as accurate as anything I've seen around here.
2. My approach will be to maximize her $$ once I am gone, unless we need the money earlier.
Using your PIA of 2899, I get yearly numbers of -
Age 70 = $63,314 for both of you, and $45,920 if you pass 1st.
Age 66 = $51,940...