Partnering with family member, don't want her on the loan

[Bassma Mancilla]

Hi everyone, 

So, while shopping for financing, I've been told that for investment properties, I cannot use "gift" money. Really it isn't gift money, as it's going to be a partnership between a family member and I. They give me part of the downpayment, and I split any cash flow with them while I handle everything. I want to be the only one on the loan, as I want to protect her from any financial fallout in the even anything happens. 

Can I wait to close, and then have her send me the money? Or is this a problem if it's after the fact? The lender said my only option would be to allow the money to season for a couple of months and then proceed. What would you do?

Disclaimer: this is my first time shopping for an investment property so it's all new to me.