We bought home from Mother - it was never her primary residence so I don't think the exclusion would apply in any sort of way (but it was her only mortgage). It Appraised 170K.  Sale price 150K (30K of the equity was used as our down payment so our loan was only 120K). She orig bought home for 137K. So

1) is the gift of equity $20k (diff between appraisal and sale price) or the 30K we used as the down payment or both at $50K?

2) Do we only report gift from 1 less the $30K permitted in a year or full gift?

3) Would she pay capital gains on the 13K  (diff of sale 150 - 137 original) or not at all since she did not make anything as she gifted us the diff as equity - she got no cash or gain from the sale -it was only just in her name on paper?