Ashton won in a last-leg decider to overcome Sherrock and in doing so, is the first woman to win a PDC card at the Barnsley Metrodome.
Sherrock suffered a shock defeat in the quarter-finals to Lorraine Winstanley in Events One and Ashton would go on to win the tournament.
The 'Queen of the Palace' would get revenge over Winstanley in Event Two but could not progress past the semi-finals as Ashton beat her 5-4 before a 5-3 win against Ireland's Robyn Byrne in the final.
Ashton, from Bolton, had an average of 80.14 in the final and won £10,000 prize money for both tournament wins.
The likes of Deta Hedman, Rhian O'Sullivan, Corrine Hammond and Laura Turner return on Sunday to battle it out in the next series of events.
The next weekend of the Women's Series is set to take place between April 30 to May 1 in Wigan followed by the third on June 25-26 back in Barnsley.
The other two weekends take place on April 27-28 and October 29-30 in Niedernhausen and Wigan, respectively.
The two players who finish with the most points from the final PDC Women's Series Order of Merit will automatically qualify for the 2022/23 World Darts Championship and 2022 Grand Slam of Darts.
Prize money for the year's 12 events will decide qualification for the Women's World Matchplay which will take place later this year.