If you google kangaroo vaginas (as I did after receiving your A2A), you will find dozens of lurid 'science is weird' websites.
What are the differences and similarities between the anatomy and physiology of a cat and Canis familiaris, ( a eutherian mammal ) and the anatomy and physiology of a kangaroo?

The young kangaroo is raised in the pouch until it can survive outside. The pouch is so important to the development of the species that it is the source of the name of the entire family. The pouch is a very important part of the female body when it comes to reproduction. Next, watch a baby koala joey peek out from its pouch, see how a baby echidna (a puggle) hatches from an egg, and from TED-Ed: The three different ways mammals give … A kangaroo’s joey is about the size of a jellybean when it leaves the vagina, and it must endure an arduous crawl into the pouch. The term kangaroo, most specifically used, refers to the eastern gray kangaroo, the western gray kangaroo, and the red kangaroo, as well as to the antilopine kangaroo and two species of wallaroo. They have a unique … When the mother's pouch becomes free, the next baby will be born and move into the pouch and the fertilised egg "on hold" in a uterus will start developing into a new foetus. A small bag often closing with a drawstring and used especially for carrying loose items in one's pocket.

The soft, woolly fur can be blue, grey, red, black, yellow or brown, depending on the species. In malacostracan: Reproduction and life cycles …embryos develop within a thoracic brood pouch, the larval stages are suppressed.

... Because they have two uteruses plus a pouch, female kangaroos can be perpetually pregnant. This is one of the easiest ways to be able to tell which sex any Kangaroo you see happens to be. Shutterstock/goldenjack A joey can be born as small as a grain of rice or as big as a jellybean .

Kangaroo genitals are weirder than you ever thought possible. This is where the young called joeys will stay until they are old enough to care for themselves.

Only female kangaroos sport pouches, which contain mammary glands and hold their joeys until they are ready to leave the pouch after an average of 46 weeks or so. Kangaroo, any of six large species of Australian marsupials noted for hopping and bouncing on their hind legs. Anatomy: Roos and wallabies range in size from 2 pounds (the Rock Wallaby) up to 6 ft and 300 pounds (the Red Kangaroo). As you learn more about the body of the Kangaroo, you will certainly appreciate all that they have to offer. Introductory information such as outer visual aspect and behaviour will be discussed, such as tallness, hair coat, velocity, and more.
Conservation status. Oh yes, it's true -- marsupials, including the most popular one, the kangaroo, are equipped with a total of three vaginas. A recent episode from Smarter Every Day delves into the mysteries of the kangaroo pouch, where joeys nestle in to feed, eat and sleep for an average of 46 weeks before leaving.

Talk about marsupial maintenance!