Cornsnake not growing

I got my corn about 9 months ago as a hatchling. She's a root beer, which is a cross between a corn and a great plains rat. She was as thin as a pencil, so of course, I fed her one pinky once every 5-7 days. Two months ago, at the 7 month mark, I realized she hadn't grown at all. She had shed two times, but there was no size difference. At that point, I decided to see if she'd eat twice a week, which she did easily. She has never missed a meal. I found that she was still hungry after feedings, so I started feeding her two at a time. I figured wild corns don't find a single pinky, they find nests, so she should be capable of taking at least two at a time. She'd eat another if I let her and she did once with no problem, but that's out of my comfort zone. She has had no issues whatsoever. Now, I've been feeding her approximately 2-4 pinkies a week for two months and she's grown a liiiiiittle. She has shed once or twice and is a slightly thicker pencil now. Not even sharpie-sized, or pen-sized for that matter. She's always been active and perky, just tiny. I've read about corns that stop growing for a time and then shoot up, but I haven't read anything this extreme. She's not too thin or fat. Pinkies make a sizable lump in her, so larger food items are not an option. She's been on pinkies for 9 months. Should I be worried?

Note: I'm sorry I don't have weights. I made the mistake of not weighing her consistently after I had no issues at all with my male hognose. She's also a fiesty little thing, and it's difficult doing it without thoroughly stressing her out. I got complacent with her, but she's never rejected a meal, never regurgitated, and her sheds are always good. In the beginning, I had to put her in a deli cup in the dark to get her to eat, but that only lasted about 4 feeds or so. The problem was more that she was scared, not that she wasn't hungry.