@Christopher1401
I am afraid I agree with @M199 . While you would think that people would be grateful for you being more accommodating (and sometimes that is the case), there is a reason for the saying, "Give them an inch and they'll take a mile."
You agreed to an early check in of 2pm. Instead, your guest shows up just after 12. She was already showing disrespect for you and your rules and boundaries. This is the point where, awkward as it is, you have to politely say, "I'm really sorry, but we need to stick to 2pm as agreed."
I had this problem when I first started hosting and I learnt the hard way. I remember in particular one couple who asked if they could drop off their bags early. I said yes, but made it quite clear that they would need to come back later to check in properly so I could show them around as the house tour is important. They agreed in writing that, yes, absolutely, they understood that and that's what they would do.
So, they came with their bags and then wanted to put them in the room, use the bathroom, change etc. I explained that was not possible because I am still cleaning. They refused to leave until they had access to the bedroom, bathroom and I gave them the keys because they were not willing to come back to check in at a later time. They would not budge on this.
So, what happens? They rated me down on cleanliness and especially the floors. Of course, the floors were all freshly vacuumed and mopped before their check in time, i.e. when they eventually came back.
They were not the only ones. I've had guests turn up outside my door six hours before check in and the first thing they wanted to do when they entered the house was use the washing machine!!
Anyway, after the couple mentioned earlier, I made it clear in my house rules, no early check in, no early back drop offs. Of course, I do allow these sometimes, but at my discretion, and if it suits my schedule. Any guest who insists on it is told very simply, no. It doesn't matter how many times they ask.