Gf decided to gain after not liking it but loves it now

M23 and F24, she’s never had the thought of getting chubby or becoming a bbw but now she loves it and wants more. At the start of the relationship she was 175 and after 11 months, she’s now 253. She plans on to keep going and keep eating as I encourage her and feed her. She wants to gain more and be 300 by the end of the year. Is gaining 78 pounds in 11 months good? She wants to gain more and she’s been eating more and more. We would go to buffets and everything and eats the place up. She loves her figure and the progress and doesn’t plan on stopping.