Would a baby monitor work? It would require a separate monitor but otherwise provides the functionality you are looking for. Something like this: https://www.amazon.com/Infant-Optics-DXR-8-Monitor-Interchangeable/dp/B00ECHYTBI?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&psc=1&smid=ATVPDKIKX0DER
We could have gone cheaper, but nothing had ratings as good, or as many features. There are more popular Motorola models, mbp36, but they didn't have nearly as many positive reviews. I've tested it from the upstairs nursery to the basement and back yard with no issues or interference.
Price fluctuates between $209 and $171 (got lucky when I bought it for that a month or so ago).
Pick a model you like, and use camelcamelcamel to watch the prices for you.
Edit: Features I wanted include talk back, pan and zoom, expandable by adding another camera, good night vision, large viewable handheld monitor, good battery life, optional wide angle lens for when she's older and moving around her room and a far reaching range that didn't interfere with my WiFi.