When you say “sibling discount” do you mean a prorated amount at the exact same school for siblings?
Or…
Is this a situation where, for the purposes of parental or cultural pride, your sibling has to also receive a scholarship/not pay full freight?
“Discount”, and forms of merit and need-based aid are different things. If you’re asking if, at UMD, they offer discounted tuition to families based on the number of siblings enrolled, that should be easy enough to find on their website, or with a quick call to admissions.
IF you’re asking about the impact of EFC for need-based aid for collegebound siblings if another sibling has a full-ride at any college, that’s a far more complex question, and the answer is, “it depends…,” on the specifics of your award, and the tax implications.
IF you’re a full-pay family, and this is about pride or cultural expectations, that’s a beast that isn’t addressed by admissions and financial aid departments at colleges and universities. For practical purposes, it shouldn’t matter (for a full pay family) if one sibling gets “a discount” and another doesn’t. The family is still coming out ahead by not having to pay for the one sibling who got a full-ride. The other sibling(s) start at ground zero for what the family can afford, and where they can be accepted. Colleges/Universities aren’t going to say, “Jennifer isn’t going to get a scholarship, because big brother Ben got one.” Jennifer will be weighed on her own merits. It definitely doesn’t make sense to walk away from a full-ride just to save face for a sibling who may or may not get merit awards (aka “discounts”).