Seventh-Day Adventists do celebrate Easter. Unlike certain Sabbattarian groups they even believe that He was crucified on Good Friday and rose on Sunday. (This is as opposed to a handful of Sabbattarians and others, who believe that Christ was crucified on a Wednesday and rose from the dead after sunset on Saturday night. There are complex reasons given for this speculative theory, the chief being that it ensures that Christ was buried a three full days and nights).
The imprtant thing to realize is that Seventh-day Adventists DO believe the conventional teaching about Christ’s death and resurrection, and they DO recognize Easter as a holiday.