A simple way is to look at the house itself, is the zhen (east) and sun (south east) section missing? If they are not missing then it's very fortunate. In the bagua the zhen and sun section represent eldest son and the eldest daughter. Activate this section with plants (pomegranate is my choice) so they grow strong and healthy. (just my hunch, activate the SE section with a pomegranate plant, a fruiting tree if possible and tie some red ribbons on it).
Also look at the chien (North east-represent the patriarch of the family) and kun (south west-the matriarch) section of your space (ie bedroom, study, sitting room), you can also put a dolls, picture of a baby in those sections.
Happy trying
