If the requirements are met grant redress but the redress is the score remains the same. This is the only fair result. 

Under 61.4(c), and given a two-race, one-day event, give B redress only for the race nearest in time (Race 1) and score Race 2 DNC. For Race 1, use 61.4(d) to determine B’s probable finishing place from credible evidence (recent comparable results, practice/qualifying performance, rankings if relevant, and reliable testimony), then award B a Race 1 score consistent with that probable result. Race 2 remains DNC (Case 116).

If I read your post correctly, Boat B was unable to race any of the races in the series, so I don't see how to apply average points, since no race was completed. Is that a fair description of your situation?

Requirements for grant of redress are met. However, she has not sailed in any race and it would not be fair on the other boats to give her a position based on any previous performance. So I agree that the redress be granted and the redress is that there is no change to her score.

Agree with Mark, Satish, can't give her a position with no races completed. Liaise with organisers, see if they will refund entrance fee, or anything else that they can do. 

Thank you for your comments!
This was a real case we had in Argentina at ILCA 6.
Boat B went back to the club and didn't request redress, and the RO didn't take any action either.
Boat A RET.

Cheers !!!!!

Question about boat A penalty I can understand her score race one as RET. Does that also mean RET for the whole series while boat B is unable to sail? 
We have often talked about this at the club with no definitive answer.

Also under good sportsmanship why didn’t boat A offer to lend her rudder to boat B for the second race, as it’s one design class they should be interchangeable. 

Thanks Nick

Somehting I have seen IJs I have worked with is to ask what redress they believe is appropriate. This is a tough one but in such a situation how does one come up with redress that is "as fair and arrangment as possible for all boats affected". Even if the person had done well in lead up regattas, they are different fleets in different conditions and potentially even different equipment (save the good sails for the big races) so I would have trouble considering this to give any meaningful redress. Without any mark rounding information or rough placement at the time of incident I don't believe you could assign any place to the affected boat. Sometimes its a cruel sport but that's the way it is.