What can I do to help improve college app?

Have sibling that will be a rising sophomore(16 before 2026 summer) and was wondering if you all have any advice for what my sibling can do to stand out to colleges. she’s interested in CS/Computer Engineering, and has around a B+ unweighted GPA from 9th grade. I’ve been trynna do research myself, but all of the programs I found online are extremely competitive and I think her GPA might be too low to get in although I definitely will encourage her to apply. Are there any semi-competitive activities she can do to help boost her application? Also, was just wondering outside of just summer programs what she can do in the CS-related area to help show her passion towards this subject? Thx in advance!