While all those made Sorcerers by birth or fate have a sixth sense that gives them an innate understanding of the Weave from which all magic comes and allowing them to observe and influence their spells, those of the Weave Witness variety are more concerned with the magic of others.  For what is the point of power if kept to one's self?  You can learn new spells by observing them being cast, and even exert your Metamagic manipulations on spells cast by your allies, and perhaps even your enemies.

Features:

• Witness to Wonder: Use Detect Magic faster and without Concentration.
• Mimic Magic: Learn spells you've seen or heard for a short time.
• Spell Editor: Enhance Ally's spells with your Metamagic
• Woven Defense: Reduce all magical damage
• Mantle of Folly: Redirect an enemy's spell.

Witness to Wonder

You can spend 1 Sorcerer Points to cast Detect Magic as a bonus action, when cast in this way it does not require Concentration and its duration lasts an additional 1 minute per your Sorcerer level.

Mimic Magic

You pick up on the magical tones or gestures of spells. If a spell has a verbal or somatic component and you can hear or see (respectively) the caster you may use your reaction to roll a Charisma check with which you are proficient to Mimic the spell's structure, if you succeed this spell becomes a Sorcerer Spell that you know until you replace it or forget it. The DC equals 8 + twice the Spell Level.
You may know spells in this way with a total level equal to your Sorcerer level. You can remember no more than half this amount (rounded down) through a Long Rest, or spend 1 Sorcerer Point per additional level after the Long Rest, at 11th level, you may spend 1 Sorcerer Point per 2 levels.

Spell Editor

As a Reaction you can apply your Metamagic to other caster's spells if they are willing, and the caster may expend a Spell Slot to reduce the price of your Metamagic by up to the price of the Spell Slot expended.
When you use your Spell Editor feature using your Reaction, you may use Spell Editor an additional number of times until the end of your next turn equal to your half your Charisma Modifier, rounded up (minimum 1).

Woven Defense

Your observation of the Weave grants you defense against those that wish you harm. You take 1 damage less for every damage die rolled unless the damage is Bludgeoning, Piercing, or Slashing. As a reaction, you can either extend this benefit to other creatures you can see up to 60 feet at a cost of 2 Sorcerer Point to protect a number of creatures equal to your Charisma Modifier, or 3 to protect twice that many. Alternatively, you may spend any number of Sorcerer points to reduce the damage to yourself by 2 per point spent.

Mantle of Folly

Your perception of the Weave is as clear as your perception of the Material. You can use a reaction to seize control of an Enemy's Spell by spending Sorcerer Points equal to the Spell Level.
To do so you must be in the target range or 30 feet (whichever is larger) and roll against a Spell Attack the save DC, if successful you may choose the target of the spell and apply any Metamagic you see fit.
If the spell's effect is continuous, your control over the spell only lasts until the start of the original Caster's next turn, at which point they regain any control, if the spell allows for such control on subsequent turns. If continuous effects can be ended by the caster, they must succeed a spell attack check against your spell DC in addition to any normal requirements.