Marguerit Maida

Marguerit Maida was a highly experienced mercenary and former member of the Trans System Federation, hired by Paul Torgal to protect the Degasi from pirate raids. Marguerit and Paul didn't get along well and argued often about where to establish themselves. Marguerit wished to go deeper into the sea, but Paul wanted to remain on the Floating Island. In the end Marguerit had her way and they set up habitats in the Jellyshroom Cave and later in the Deep Grand Reef. Paul allowed this to happen because, despite being the captain, he knew that he and Bart needed her to survive.

Marguerit's considerable experience was demonstrated on multiple occasions, once when she wrestled Stalkers and took their teeth by force and again when she brought a nearly dead Reaper Leviathan to their base in the Deep Grand Reef, and was last seen clinging to the Reaper Leviathan responsible for the destruction of that base, having stabbed a jagged piece of metal into its neck.

Marguerit seemed to have disappeared after this account against the reaper leviathan, although with new information from Subnautica: Below Zero, it is shown that Marguerit survived deep in the icy biomes, being present on the planet for the last 12 years. It is unknown as to whether or not this information will make the final game, so don't think of this as canon just yet. It is also unknown how Maida could have survived the Kharaa for that extended period of time, at least before Ryley came and helped spread the cure.

Bart Torgal
Marguerit and Bart seem to get along, and it is highly obvious that she prefers him over his father. An example of this is when Marguerit planned to leave the Torgals while they were sleeping, take what she needed and go off on her own. However, while expressed relief at the prospect of leaving Paul, she couldn't bring herself to abandon Bart, claiming that he wasn't "so bad." Whether their friendship caused her to stay is unknown. Throughout their time on the planet, their relationship is further explored, with Marguerit capturing specimens for Bart to study. When she found an alien tablet in the ocean she gave it to Bart to study, showing that she trusts him. When Bart realized that they were infected with an unknown pathogen, she took extreme measures to capture specimens for him. Despite their disagreement over her methods, the two shared a friendly relationship.

Paul Torgal
Marguerit's relationship with Bart's father was tense, to put it mildly. Paul was bullheaded and stubborn, set in his ways and the belief that his way was the only way. But Marguerit often did things her own way and refused to even consider Paul's point of view. An example of this is when she proposed to move to the Jellyshroom Caves, which Paul flatly refused multiple times. She was aware of and chose to ignore Paul's dislike towards her friendship with Bart. She also ignored his frantic reactions to her actions, such as bringing back a severely injured Reaper Leviathan on the back of their Cyclops, as she merely stated Bart needed a "test subject."

Trivia

 * Marguerit means "daisy" in Danish.