Charlotte Edwards made 60 and Shrubsole took 2-27 as England beat Bangladesh by 36 runs in their first game.
"We probably wanted 20 more runs. There were a couple of dropped catches and at times we were a bit impatient with the ball," Shrubsole told BBC Sport.
"There are plenty of things to work on and hopefully we can put them right."
With the top two advancing to the semi-finals, Group B is currently led by West Indies, who have won both their opening games, while hosts India suffered a surprise two-run Duckworth-Lewis defeat by Pakistan.
"It only helps us if we win. If we don't win then that India result doesn't help us at all," Shrubsole added.
"It is good for women's cricket that the games are becoming more competitive. You've seen how South Africa have progressed in the last couple of years and now Pakistan and Sri Lanka.
"We know how much India have come on. They beat Australia in Australia not that long ago so they are a dangerous side and will be coming here with a point to prove after the game against Pakistan."
Asked about the influence of new coach Mark Robinson, formerly in charge of Sussex, she revealed: "He has challenged us straight away, particularly with the bat, to play some more positive, aggressive cricket.
"One of the first things he said was 'I hate safe cricket'."
England bowler Anya Shrubsole says they must retain their focus in Tuesday's Women's World Twenty20 meeting with India in Dharamsala.