There's no doubt that Daenerys's right-hand woman would be willing to protect and raise the khaleesi's child in the event of her untimely death. Though Missandei is unlikely to ever bear natural children due to her relationship with Grey Worm, who has been castrated, she is an exceptionally patient, compassionate, and loyal teacher. Missandei adores and respects Daenerys, and would undoubtedly treat her orphan as an extension of its mother, sharing incredible tales about the "Mother of Dragons" to teach the child all about the mother it lost.