Observation is for one individual, plants can both flower and fruit at the same time, if you wish to have observation for eggs, you can upload the same picture (or cropped) and add that annotation, or sacrifice the female and only add egg annotation or juvenile in both cases respectively.
I too wish we could annotate for the adult and young both present in the photo or the eggs and adult, or both male and female of a pair, but it’s just not iNaturalist practice. Each observation is, technically, for a single individual. Sigh.
The iNat project, Multiple Life Stages has created some observation fields that can be used regardless of whether or not you decide to add your observation to the project.
Here’s an example of mine: Mother Wolf Spider w/ juveniles. Notice I have left the “life stage” annotation blank, but under “observation fields”, I have added some reliant fields.