Poonam's 75 came off 56 balls with 10 hits to the fence while Thirush Kamini took 72 balls for her 56-run knock which contained seven boundaries.
Though India defeated the West Indies by a huge margin of 105 runs in the opener, Indian skipper Mithali Raj said she was nervous during the Windies' chase.
Chasing 285 for a win, West Indies were bundled out for 179 in 44.3 overs.