The courts have received and acted upon, and will continue to receive and act upon, as Priority #1 matters all applications for emergency orders of custody pursuant to CGS 46b-56f, including the scheduling of hearings in cases where ex parte relief is granted. That includes applications alleging such harm based on withholding of parental access. The determination of whether the withholding of access in a given case creates "an immediate and present risk of physical danger or psychological harm to the child," and if so what relief should be granted, rests within the sound discretion of the judge reviewing each particular application.

Based upon what you have written, technically, you have agreed to forego the visit and now want to withdraw your agreed to modification of the visit. If you file a motion for contempt now, you won't be heard until after the courts re-open for normal business and all it will do is make you look like someone who wants control regardless of what may be in the best interests of the child.
If "she ain't leaving" are her words, realize that those words are a signal that your ex is scared and fearful for her own and her daughter's safety. Have a face to face conversation with her about visitation and together both of you go over what is known about the dangers of COVID-19 together using gov't resources, then work out visitation in light of what is known. Trying to force risk factors on her will not work; she must come to it on her own.