Now I'll dive into the Opal is not 5'10 project, I have done much research so uwu

Point 1. Calico is not a breed, it's a fur pattern and Maine Coon cats... Even males wont weigh any more than 18 pounds when healthy, 5'10 that's 177.8 cm... I feel like these dimensions don't add up, unless Opal is extremely skinny with the height, which is unlikely for a Maine Coon as they are a fluffy and rather chonky breed while still tall.

Point 2. The average 5'10 female human weighs 135 - 165 pounds, the generally at most 18 pound Maine coon cat is very far off.

Point 3. 177.8 divided by 150 (Middle of average weight) is 1.18533333333 pounds per cm of height, now if we divide 177.8 by 18... that's 9.87777777778 pounds per cm, now if you use grams/kilograms like me. That's 4.480484632556564 kg per cm for Opal and 0.5376581559051548 kg per cm for average human

Need I say more? I believe I have proved the point that I definitely didn't need to