Thirlwall, who was named as the club's honorary president in August, is one of 750 new shareholders as the club takes its first steps towards fan ownership.
The initial target for the investment round was £250,000, but the club has confirmed over £280,000 worth of shares have been snapped up so far.
South Shields FC Chairman Geoff Thompson said: “We are thrilled with the response we’ve had to our investment round.
“To hit our initial target so early was something which filled us with so much pride and optimism for the future.
“It’s hugely exciting that more than 750 people have shown their support to us in this way and for Jade to be one of them is just another example to show how committed such a global superstar is to not just the club, but her hometown.
“We will continue to welcome new shareholders until the campaign ends on November 28th so any supporter or potential investor who is interested still has some time yet.
“We have had a remarkable journey over the last five-and-a-half years and receiving investment of this nature will help us greatly to continue delivering on our ambition to rise through the football pyramid as a sustainable, community-based club.
“I’d like to say a huge thanks to everyone who has invested so far.”