The timeline above is a very common way for birthing mothers to take their parental leave.
(But it's not the only way to take your leave.)
Non-birthing parents often take some time off immediately when the baby is welcomed home - in order to care for the birthing parent, as well as share in the childcare duties.
Most employers allow parents to break up their parental leave into shorter chunks, such that they can use up their full leave but spread out over the first 12 months of the baby's life. Using that flexible policy, some non-birthing parents will return to work before using all their parental leave, and then use the rest later in the year.