Mary added a total of 7 stickers/page * 6 pages= <<7*6=42>>42 stickers to the 6 other pages.
In total, Mary added 3 large stickers + 42 stickers = <<3+42=45>>45 stickers to her journal.
Since she started with 89 stickers, she now has 89 - 45 = <<89-45=44>>44 stickers left.
#### 44