Advice, please?

Redirect her hands and encourage "gentle touches" (she can still touch, just not by pinching), and if it gets bad, put her down. Make sure you say out loud that you're going to put her down and why, then pick her up again a minute or two later and try again. She should get the message eventually.

If she'll take one give her a lovey or maybe a blanket that she can play with and pinch. Some material she can handle that she can soothe on (which is likely what the pinching behaviour is).

Lots of sensory toys to explore with x

I mean she's only 7 weeks... She's not going to understand gentle hands or what she's doing. You can just hold her hands that's it. Still a newborn

I wouldn't call this a "behaviour" that needs to be discouraged at 7 weeks. She's exploring the world around her so let her do that. Surely a newborn is not causing any harm ? Make sure her nails are always trimmed so she doesn't scratch herself and offer her some sensory blankets/toys to grab.

It isnt a behaviour. She is a baby? She isn’t doing any harm

You don't. You let them explore the world around them, and keep their nails trimmed if the pinching hurts you in some way. They have no concept of what they're doing or why, the world is brand new to them and they do not have the conscious thought of wanting to pinch someone, or what it even means. It will stop on its own eventually.