When did your bad-napping baby start napping longer?

Va

Baby is 6 months old. She’s been learning to fall asleep on her own, no pacifier, but most of her naps are still only 30-50 minutes long (30-40 really), and I’m exhausted. She takes 3 little naps a day usually. I cannot express how badly I wish she would just take two 1.5 hour naps a day, but I’m trying to cope and roll with it. But I’m so frustrated and losing hope that she’ll ever nap well 😞

If your baby did this, when did it get better?