Betty Boop is 14 months old. Up until she was 10 months old, I constantly taped her ears. It definitely helped them to stand up. I never gave up and it paid off. However, I've noticed when she plays and gets tired, and when she needs to have her ears trimmed, her right ear will flop over. It will always stand up given time, though. I really want them both up. Just my preference. But, if she wants one ear down at times, that's "eartirely"
up to her.