Questions about booking a short flight with a toddler

My mom has some Delta airline miles she wants to use to fly my 2 year old and me to see her at the end of August. A few things about the flight followed by a few questions:-Flying from Albany to Detroit. I've made this trip by myself several times and it is usually the smaller commuter jet with one row of single seats and one row of double seats.-Usually an extremely short direct flight - maybe 2 hrs.Now for the fun questions:-My daughter turned 2 at the beginning of July. She is a small two year old. I don't have any fears of her being a pain on the flight (fingers crossed) because she is super chill. However, I'm 100% convinced she will want to sit on my lap regardless if she had her own seat or not. Can I cheat the system (please don't yell at me), book her as under 2, and let her sit on my lap?-From everywhere I looked online, it does not appear that Delta requires identification for my child. Is this usually the case? I would totally bring a copy of her birth certificate no matter what for emergency purposes, but do they ever ask for it out of the blue?Monetarily it does not make sense for us to purchase a seat (the free mileage is good for one seat) just for my girl. Morally/ethically/whatever you want to call it makes me a little apprehensive. However, I do remember my parents saying I was 3 when I was really 4 to get into Disney for free :). I, and they, turned out ok.Thoughts, advice, pleasantries? Thanks in advance! via /r/Parenting http://ift.tt/2aCi4yK