As a maiden she may have forgotten to read the manual, and won't show any signs, but she doesn't look very close to me at all. Her vulva have not lengthened appreciabely, and though I can't see inside very well it still looks pink rather than deep pink to raspberry red. She looks like she has control of her tail and isn't at all sunken at the tail head. She also looks round still at the bottom of her belly and she's still rounded out to the sides rather than V'd down at the belly and almost flat sided again.
If you get a water testing kit or a foal prediction kit will help you out quite a bit. Predict-A-Foal
I like the Predict A Foal kits, I have had good accuracy with them.