There's a few things that tell me that she's gravid:
1) Here's a picture of her ovulating on June 5th
2) She won't eat (and hasn't since March) and she's my best feeder.
3) She breeds every 2 years like clockwork.
4) She's the fattest Ball Python I have and hasn't had any caloric intake since Marh (unless water has calories?).
5) I've never had a Ball Python lay inverted unless it was gravid or it had eaten. Especially inverted like that! I've only seen Burms lay like that.