Which one is a correct sentence?

→ Better হলাে well এবং good - এর comparative form.
→ সুতরাং, better - এর পূর্বে more বা  comparatively বসানো যাবে না।

আর Comparative Sentence-এ good এবং best এর ব্যবহার ভুল। 

Correct Sentence: Mina is better today.

Example Sentence:
1. She performed better in the second round of the competition.
2. With consistent practice, you'll become a better musician.

Source: A Passage To The English Language: S. M. Zakir Hussain.