Everglow's previous release before "All My Girls" was the single "First," which was released on February 1, 2022. "All My Girls" was released on March 21, 2023.

To calculate the gap between these two releases:

• From February 1, 2022, to February 1, 2023, is one year.
• From February 1, 2023, to March 21, 2023, is an additional 1 month and 20 days.

So, the total gap between the two releases is approximately 1 year and 1 month.

If you have any more questions about Everglow or their music, feel free to ask!