Beatrix/Relationships

Unnamed Younger Sister
It's unknown what the relationship was with Beatrix and her younger sister prior to her death. But after her death, Beatrix would travel all over the world to find her niece.

Niece
Beatrix appears to greatly care about the well-being of her niece (heavily implied to be Alpha), traveling the world in hopes of finding her and threatening anyone who might have some information on her whereabouts.

Cid Kagenō / Shadow
The two had met during the Bushin Festival. Beatrix not only picked up Elf scent on Cid, but also sensed great power within the boy. She asked him if he met her niece to which he denied. When being asked about if any of the Bushin Festival's fighters had caught her interest, Beatrix declared it to be Cid, claiming that he'll be strong.

When she fought Cid as Shadow, Beatrix is strong enough to fight Shadow to some extent, but when Shadow started to get serious, she couldn't stand against him. She is the only one who understands that Shadow's sword fights only with swordsmanship without using magical power, and Beatrix acknowledged him as an incredibly powerful warrior with his strength and skills she described as no different than nature itself.

However, she was even horrified the level of power Shadow possessed. After her defeat against Shadow, Beatrix herself sets out on a journey of training to improve her swordsmanship from scratch.

In Master of Garden, the two meet again by chance to save two children from abductors. Beatrix began to develop romantic feeling for Cid when the former was saved by him from an ambush.

Iris Midgar
Beatrix met Iris when the former arrived at Midgar Kingdom and she collaborated with the princess in hopes to find her niece. The two respected each other and worked together in taking down Shadow. However even with the joint effort of the two former champions, they were unable to defeat him.

In the anime, following the fight and upon seeing Iris's complete mental breakdown, it's implied Beatrix's respect for Iris as a fellow warrior has diminished quite considerably when she sternly advised the princess to not be obsessed in fighting Shadow.