Show like Hamtaro by this logic are nothing but fuller as there is no on going plot going on, I have seen the subs and raws and she does expands.
By seasons 5 & 6 her roll is less prominent but she still gives you a good time (Such as Laura as a Power Ranger and Laura telling a 5 year old boy that "It's not going to work out between us").
The OVAs and movies however are another story, Laura only shows up for a around a minute (a few minutes in the first OVA and only a for a few seconds in the 4th OVA), when in the movies Laura is the plot point but for the rest she is barely used.
Laura does not have a static personality, she is a kind, gentle, bright and energetic person who hates people who cross her path (Roberto).
If you bother with her, you will fine out that Laura is a excellent character and is just as good as Babs Bunny & Slappy Squirrel hence why Laura was even made, to show that not all girls need to be sex toys, dolls and have magic powers to be useful, you can set them up the same way as a male character and it will work just as well as them.