The Supreme Court's power of judicial review isn't defined in the text of the Constitution. It was applied by the Court to itself not by interpreting the text but reading between the lines and deciding it
should have been there.
It seems to me that if we can accept that then we've already accepted that the Supreme Court can imagine new rights with no textual basis in the Constitution. After all, the Constitution isn't meant to describe an exhaustive list of rights so much as maximally bind the Federal government as to what rights it is allowed to abridge. So the concept of "rights having a textual basis in the Constitution" is nonsensical, ̶a̶s̶ ̶t̶h̶e̶ ̶C̶o̶n̶s̶t̶i̶t̶u̶t̶i̶o̶n̶ ̶i̶t̶s̶e̶l̶f̶ ̶c̶l̶a̶i̶m̶s̶ ̶t̶h̶a̶t̶ ̶r̶i̶g̶h̶t̶s̶ ̶a̶r̶e̶ ̶g̶r̶a̶n̶t̶e̶d̶ ̶b̶y̶ ̶a̶ ̶"̶C̶r̶e̶a̶t̶o̶r̶,̶"̶ ̶n̶o̶t̶ ̶a̶ ̶g̶o̶v̶e̶r̶n̶m̶e̶n̶t̶.̶ (edit: ... ok that was in the Bill of Rights my bad but still, rights aren't defined by the Constitution.)
Also, RBG believed abortion could be supported as Constitutional right, but she preferred an argument on the basis of equal protection over the arguments from privacy that underpinned Roe V. Wade, which she believed were too weak and easily undermined (and she was correct.)
The only relevant question per the Constitution is not whether the right to an abortion exists, but whether the Federal government should be allowed to interfere with that right, whether states should be allowed to interfere with that right, or whether that right should be left in its default state of being claimed by the people.