Charity Navigator is the gold standard for rating charities for donations. The give St. Jude's four stars (out of four)
https://www.google.com/search?q=charity+rating+st+judes&rlz=1C1CHZN_enUS971US971&oq=charity+rating+st+judes&aqs=chrome..69i57j0i10i22i30j0i390l5.5419j0j15&sourceid=chrome&ie=UTF-8
And they give the Shriners four stars plus their highest recommendation "Give With Confidence" rating.
https://www.charitynavigator.org/ein/362193608
The only reason they didn't give St. Jude's their Give With Confidence recommendation is because Pro Publica did an article accusing St. Jude's of not doing enough to help their families. The complaint is that while St. Jude's covers the child's medical care and one parent's lodging, it doesn't offer lodging for the second parent and doesn't do anything for income replacement for the parents when they take time off to take their child to the hospital. St. Jude's simply doesn't offer those services. Pro Publica seems to think they should, and that they have enough money to do so. While the concern is real, it doesn't seem to be a fair nock on the charity. Charities are rated on how much of a percent of their income they spend on programing and St. Jude's is not hoarding money, even though they have a large foundation. It would be a slippery slope to start making direct cash payments to families in need, which St. Jude's is probably not well set up to do. Other charities focusing on that need would be in a better position to issue vouchers or cash assistance.
So to answer your question, yes, both the Shriners and St. Jude's seem like good places to put your charity contributions.