Power pump do help a lot as demand means supply. You can add in one power pump every night and continue until supply is stable. It will be better if you can direct latch as baby can extract milk better than pumps can.
If due to various reasons you are unable to direct latch, you can consider to pump 3 hourly for minimum of 15 minutes to maintain supply. Remember to drink more fluid and be hydrated if not supply can be affected.
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