Form 15h estimated total income

I need to fill form 15 h for my mother. She has invested an amount of 1L for which she gets an interest of 3000/- every quarter. I need to submit form 15h every quarter. I have below questions

1. What should be the value for column 15 - Estimated income for which this declaration is made? Should it be 3000/- (quarterly) or should be the annual amount i.e 12,000?
2. What should be the value for column 16 - Estimated total income of the P.Y. (Present / Financial Year) including the income mentioned in point no 15? Assuming the value for column 15 is 12,000, should the value for column 16 be 1,12,000/- or just 12,000? Is the initial investment of 1L also considered as income?
3. Given that this is just the start of the financial year (Apr 2017) and I have not done any other investments, should I enter the value for column 17 - Details of Form No. 15G other than this form filed during the previous year, if any as 0 and the aggregated amount of income as 0?

Thanks for the expert advice.