I think she is. Reasons:
- No more Shichibukai status protection
- Her island and crew are very capable but too weak against top forces
- Calm belt cant protect them anymore due to new improved ships
- Rayleigh is too old. Vs an admiral + VAs he will lose, same as Garp.
- Hancock is strong but guys like Fujitora and Green Bull are likely stronger
- Her relationship with Luffy is secret. She wouldnt use him as protection as it would out the secret.
- By staying at Amazon Lily she is putting the island at risk as seen with BB hunting her
With no other choice I’d expect Rayleigh and Gloriosa to convince her that joining CG is the best for Amazon Lily and also for herself.