Kardashian already shares 4-year-old daughter North and 23-month-old son Saint with West, and is expecting her third via surrogate. She told host Ellen DeGeneres that North is excited to have another sibling.
"My daughter thinks she's really tricky," the star said of North. "We had a baby shower over the weekend ... so people brought toys and gifts. She was opening them up the next day and she said, 'Mom, since baby sister's not here, I think I need all her toys in my room.'"
"It is [a girl]," she confirmed. "North is really excited about that. She's so excited. Let's see if it lasts."
Kardashian has previously said North was struggling to adjust to Saint, and confessed in a video on her website in October that North is "still jealous" of her little brother.
"Obviously North loves Saint, she just is still jealous," the star explained.
"She needs to still get it together and warm up and be a little nicer, but I think she's getting there," she said. "I saw glimmers of hope a week ago. She's not harmful, she's not hurting him or anything. She just doesn't want boys in her room."
Kardashian told DeGeneres her baby girl will arrive "soon," but did not share a specific due date. She said she and West have yet to decide on a name for their second daughter.