5 Gallon Tank (Juvenile?) Female Betta is Making Bubble Nest

I have a female betta in an established, planted tank who has been making bubble nests lately. She has a filter and heater. The temperature is 26-27 C.

She's definitely a female-- she has the egg spot and is a whopping 1.5 inches with light coloring.

She'd been sold as an "adult" (thanks Petco), but since she was so small and nearly transparent, I thought she was a fry.

However, now she's making bubble nests and is developing a white mark on her side. I thought it might be ich, but it looks more like a pattern feature than anything else. I've heard that females might occasionally make bubble nests, but not juveniles. What does this mean? Is she matured? Why is she getting white stripes instead of getting opaque (I can see her spine)? She eats Omega One Betta Flakes and frozen brine shrimp as a treat.

 

Sometimes males will have a fake egg spot as well...so there is that, as well.

 

Sometimes males will have a fake egg spot as well...so there is that, as well.

I'm raising a mystery fish! >o<

 

any pictures?

 

any pictures?

I can put some in when I get home

 

My female did make a bubble nest, so it is not unheard of...it wasn't as big or as thick as a males' would be, but she did it! She was a female veiltale.