You don’t necessarily need to created a second collection project if you just want to see certain life stages within the first project. You can put a lot of filters into the url that aren’t available for projects or on the Explore page.
I think this section of the URL Tutorial topic will help you find the items you want to see. https://forum.inaturalist.org/t/how-to-use-inaturalists-search-urls-wiki-part-2/18792#heading--annotations