Southern Two-toed Sloth (Choloepus didactylus) - female with young

Did she act defensive to the visitors around because of her baby?

No. Do not behaved aggressively, she was very calm. Young is a male aged approximately 4 months. It is worth noting that in this enclosure where they living are another 3 adults sloths and one young (one year old) - a large breeding group!

She certainly does not appear to be comfortable in that vulnerable position on the floor.