Megan Schutt then took three wickets in the final over as Sri Lanka ended on 112 for eight before Healy (54 not out) and Mooney (56 not out) saw Australia home without losing a wicket.
The right-hander announced his retirement from international cricket at just 30 years old having debuted for the Proteas in March 2017 against New Zealand at Seddon Park in a T20I. He made his Test debut in the same year playing against Sri Lanka at SuperSport Park.
BPCL posted 170 for nine in their 20 overs. Shivam Dube top-scored with 84 off 59 balls with 13 boundaries and a six. Dube shared an 80-run fourth wicket stand with Sahil Jadhav. n their response, RBI chased down the target in 18.1 overs to finish on 172 for three.
Deepti finished with figures of three for 15 and became the first Indian to take 100 T20I wickets at Newlands as her side took a giant stride towards the knockout stages.
This was India's second consecutive win, helping them take the second spot in Group B. They are tied with England at four points but the English team sits at the top thanks to their superior net run rate.
Harmanpreet played a gritty knock of 33 while Richa scored an unbeaten 44. For West Indies, Karishma Ramharack bagged two wickets while captain Hayley Matthews and Chinelle Henry claimed one each.
India registered a thrilling seven-wicket victory against Pakistan in a humdinger of a match to start their Women's T20 World Cup with a win on Sunday at Newlands.