Lilly's fifth house holds children, and around them pleasure, banquets, taverns, plays, and messengers and ambassadors. The grouping is not random. The fifth is the house of what issues from the native and gives delight, and in a scheme where the first house is the body and the second what the body owns, the fifth is the increase that comes out of a life rather than into it.
Jupiter is the general significator, as the greater benefic and the planet of growth and abundance. Venus has a place in the reading too, because the fifth is where Venus has her joy, one of the seven houses in which a planet is held to be at home in its own affairs whatever sign occupies it.
The particular significator is the lord of the fifth, and the questions traditionally asked of it are hard and practical ones: whether it is fertile or barren by sign, whether it is free of Saturn, whether it aspects the ascendant or its lord. Cancer, Scorpio and Pisces are counted fertile signs, Gemini, Leo and Virgo barren, and the rest indifferent. That scheme runs through horary and electional practice and rests on the tradition's own reasoning about the water triplicity rather than on anything outside it.
Which is worth stating plainly rather than leaving implied. These are the tradition's rules, recorded as the tradition holds them. The atlas describes what astrologers have said about children and charts. It does not present a chart as a way of forecasting a birth.