It's been 11 days.
While roaming and other stress related behaviors can be common while they are acclimating to their new home, you should really be past that stage by now.
I would recommend checking your setup - temperature zones (hot spot, ambient, cool side), whether or not you are fulfilling her security needs, etc.
You stated that she is kept in a tank - I assume you mean glass tank? Are any of the four sides covered? How are you heating it? What type and how many hides does she have?
Rule out any husbandry issues before thinking this is normal behavior. She may be trying to wedge into that lip because either the temperature there is optimal or she feels secure there.