The ectomorph body type is lean and thin, and people with this body type find it harder to gain weight or muscle. Imagine a ballerina or a soccer player. Mesomorphs are muscly and athletic, with good posture. People with these body types find it easy to gain muscle mass, and easier to gain weight than ectomorphs. Imagine a football player or wrestler. The endomorph body has the more fatty physique, with underdeveloped muscles. They can gain muscle mass as well as mesomorphs, but they also put on fatty weight very easily. People with these body types would most likely play dodgeball or even wrestling.
Ectomorphs are generally thin/lean and struggle to gain weight however much food they consume. They also seem to have long limbs. Meshpmosprphs have wide shoulders and are have a built physic with round muscle bellies and narrow waist. Endomorphs have a wider and blocky build across the whole of their bodies than ectomorphs or mesomorphs. They have wide hips, shorter limbs, and thick ribcage.
Ectomorphs can be long-distance runners and high-jumpers. Mesophosprhs can be good rugby players and short distance runners. Endomorphs can be good wrestlers and sumo fighters.
ask more questions to open up and definitely confront the problem to her so you guys can work it out because if you don't and you both keep holding back it's not finna help nun so just go to her talk to her get out of you comfort zone. make the first moves yk don't hold back communication is key.