~Jess,
I started HRT about a week before you and this is what I've experienced so far. (on u-ionized E and P)
Oh and I am 27 and started with a BMI of 18.5 fully clothed w/o shoes.
01. Crying: I have been getting misty eyed more frequently (on the verge of crying).
02. Female orgasm: On day 7. I'm assuming this is the case because my body was euphoric for about an hour. It started with me just drifting into some very "interesting" thoughts.
03. Appetite: Picked up, I used to eat two meals a day and maybe a snack. Now I can't seem to get full for very long.
04. Fat Distribution: Mainly to my face. I don't look like I grew up starving in a camp like I did.
05. Nipples: On day 9 I noticed that they are a little more puffy, and day 10 slightly more sensitive but not by much.
06. Facial Hair: Started slowing down at about the week mark.
07. Body Hair: Started slowing down at day 3.
08. Emotions: Feel much more calm and relaxed. Things that used to set me into a rage are becoming just irksome.
09. Logic: No change, I've always tried to achieve a Vulcan-esque logic.
10. Shopping: Has become a lot more fun

, and very dangerous to my budget

. I used to be a in and out type of person, but now I can lose hours in a clothing dept.
So don't worry too much about your age. There are plenty of girls on here that have started transition in their mid to late twenties and beyond. As I have found common here though, YMMV. To put on some extra calories I have been supplementing each day with 1 cliff bar (250Cal) and 1 Ensure Plus (350Cal). At this point I feel like I will begin tapering back a bit and switching between one or the other on alternating days instead of both. I'm probably forgetting some things, but I've tried my best to keep track of what has been happening.
Have a wonderful day <3
EDIT:
11. Testicles: Day 11 on and off feeling that they are being tightened/squished. Possibly a chemically induced castration type effect, I'm not sure.