Sanding sealer acts as a base coat to protect the bare wood where she had scraped and sanded away the loose, chalky old paint. She will be able to apply coats of paint over this. It isn't necessary for this coat to be terribly smooth. If necessary, she can sand it down a bit if it's too rough.
The last time we did this, Lisa did half the porch one day and the other half on the next, but the weather is moving in on us. The instructions say not to paint in weather colder than 10°C, and tomorrow is supposed to be colder than that. So Lisa tried to cover as much of the porch as she could, leaving only a small area through which with the help of the mini-pallets we could access the front door. Fortunately today was relatively warm, and the sealer dried in a couple of hours. However, by the time it dried, conditions were unsuitable for putting any more sealer on the remaining areas, so we'll probably have to wait a few days until it warms up a little bit.
Sunday we have a National Weather Service warning of a cold snap, with a high of +8°C and a low of (gulp) -8°C. Good thing we still have about a half-pallet worth of firewood left. Lisa also cut up some of the old boards removed from the rear patio, and she encouraged me to burn them as well.