Not sure if you're aware this new pilot project that kicked in this week regarding Employment Insurance. You can now earn more money whilst on parental leave.
"Under the new pilot project, you will be able to keep 50 cents of your EI benefits for every dollar you earn, up to 90% of the weekly insurable earnings that we used to calculate your EI benefit amount."
Note that this is only applicable to parental leave and not maternity leave i.e. after the first 15 weeks.