How do I set up an Apple watch SE from a family member's 6S when my SE does not have cellular and my phone is only a 6 which will not support IOS14

You can't,here is what you need for family setup;

What you need

• An Apple Watch Series 4 or later with cellular,* or Apple Watch SE with cellular, with watchOS 7 or later.
• An iPhone 6s or later with iOS 14 or later for the initial watch setup.
• An Apple ID for yourself and one for the family member who will use the Apple Watch. Your Apple ID needs to have two-factor authentication turned on.
• A Family Sharing setup that includes the person who'll use the Apple Watch. You need to have the role of organiser or parent/guardian to set up an Apple Watch for a family member.

Can you please confirm:

When using the hardware and OS requirements noted, with my iPhone and my daughters Apple Watch (w cellular), using family sharing...

(a) will she will be able to text, share photos, email with her own account

(b) and will not receive my texts, etc.?

TIA