You have to meet 2 conditions to be eligible for Illness Benefit.
1. You must have paid 104 class A contributions since you started work - 104 contributions is 2 years, so you must have worked for 2 years (doesn't all have to be consecutive).
2. You must have 39 contributions for the calendar year 2010 - these can be a combination of paid or credited , but 13 of the contributions must be paid. The 39 (and 13) contributions must be in the same year.
If I understand your posts, you have worked either part-time or full-time for the past 7 years (apart from your maternity leave). This suggests that you've been paying PRSI contributions for the past 7 years, and in that case you should qualify.
If you contact illness benefit section (contact details at the bottom of the page I linked to earlier), they can give you more information on your contributions and entitlements.