Hi shparekh,
Thank you for posting in the Apple Support Communities. We understand you are attempting to share iCloud storage with your family.
Have you already set up Family Sharing?
- Go to Settings > [your name].
- Tap Set Up Family Sharing, then tap Get Started.
- Choose iCloud Storage as the first feature to share with your family.
- If necessary, upgrade to a 200GB or 2TB storage plan.
- When prompted, use Messages to invite up to five additional people to join your family and share your storage plan.
- Choose Apple menu > System Preferences, then click Family Sharing.
- Click iCloud Storage.
- Click Share.
If you're using macOS Mojave or earlier:
- Choose Apple menu > System Preferences, then click iCloud.
- Click Manage in the lower-right corner.
- Click Change Storage Plan.
- Upgrade to a 200GB or 2TB storage plan.
- Go back to your iCloud preferences and click Set Up Family. Follow the onscreen instructions.
- When you're done, go to the My Apps & Services tab and choose iCloud Storage.
- Click Start Sharing."
You'll find these steps here: Share an iCloud storage plan with your family
Cheers!