However, none of the below qualifies as acceptable:just put the same as last yearnah, I did not make any profit last yearI guess between $10k and $20k per property, or maybe $25kI dunno, how much expenses are normal for my business?

Plus your numbers as to profitability of the MHP are way off.  

Ofcourse you would because you could turn around sell it for a $40k profit. 

Seasoned investors could care less what the interest rates - they are more worried about profit - while the laymen sit on the sidelines waiting for (a perceived) better opportunity. 

I bought it at a good enough price I knew I could simply turn around and put it back on the market and make a little profit How did you find this deal and how did you negotiate it?

Anyone can buy a bunch of properties, can you sell them and make a profit is the real question.

Or is there an acceptable or usual profit sharing for this kind of arrangement? 

If she's a business woman then she will be open to profit sharing.

I'm happy to pay for systems to save time and guidance but the fee seems ambitious and I don't love the idea of forking over large percentage of profits to be told what I can and can't do with the company. 

For flips, I have a minimum profit potential of $40k For new construction, I look for ease of the build.