The figure behind the song dynasty in the deep palace is pregnant with an heir

There will be labels after pregnancy. The number at the back represents the time. For example, a month is ten days. You are grounded for three months, and then there will be a number behind the label. For example, being grounded 1 is grounded for ten days. Three months is ninety years old, and you can be free after nine years old.

Similarly, in the setting of the deep palace song. It takes 30 years from pregnancy to birth, and being pregnant with heir 2 means that your pregnancy time is 20 years.