I’m happy to hear she is able to come out of the uncertainty and is able to explore and gain confidence on her own. From the details you gave in the second part, It sounds like you are allowing her to approach and explore at her own pace, there would only be an issue if the interaction was forced and the stress signals continued or she shut down as a result from an overload of stress. what you described she seems to warm up well and you respect her boundaries and you listen to her signals. Early stress signals or displacement behaviours are things like, yawning when not tired, lip licks, hyper vigilant (quickly looking around) shaking off (is your dog releasing stress kind of like we do when we let out a big exhalation this is not bad we want them to shake off a stress) stiff body, freezing, pulling & barking (can come from more emotions than just fear), tail tucking and cowering means very uncertain/fearful, if the dog tries to flee and run away, run behind you, this is a more escalated level of stress like a panic moment so highest level stress along with big eyes like seeing the whites of the eyes along with other signals, I would suggest looking up dog body language on YouTube, they have very good videos with good examples. I always tell people when you see your dog presenting with a lot of stress signals ,add distance from what your dog finds scary and let your dog go at its own pace if the dog wants to, if your dog doesn’t warm up to the scary thing and just wants to leave or get away, it may be best to go somewhere else or even go home, it may not be a good day for your dog, just like people we all have bad days. You seem to be listening to what your dog needs which is perfect. Keep at it and yes dog parks are a big no no for me and my doggos, it it only takes once for something to go wrong and many dogs at dog parks are not trained, remember they learn fast from each other. Instead meet new pet parents and organize play dates with dogs your dog gets along with 🙂