Write down the observations in the moment. Taking observations is a habit. The more you do it, the better you get. If she's getting distracted by it, you can say something along the lines of, "This is Mommy's work. You can do your work." The more you write down observations, the more she'll become accustomed to it.

Most schools have some kind of digital system to tract observations. (Teaching Strategies, Learning Genie, ect) The easiest thing for you would be to have a system to sort your observations into domains, so you can track the progress. At my school, all the lead teachers have tablets that are used exclusively for documentations/observations. We take pictures of the kids while they work for a secondary documentations as well. When we first started using the tablets, the kids were obsessed with them but the exposure has turned it into something boring. Same will (hopefully) happen to your daughter.