K.S.
As a former housesitter, I would really be offended if all I got was $100 for 3 dogs & 10 days, even with the fridge full of food. It wasn't a full-time job, just side money, as would be for your sitter. Look into the price of boarding, on average it's about $15-20 per dog per day. Yes, you want to save money-I get that. But, you also don't want to take advantage of this girl. Maybe consider paying her 1/2 of what it would be to board. She really isn't "just" feeding and watering. She does still have to take them outside & clean up any messes that they might make. There is also the addes security of that fact that your home will still look like someone is home.