Things could be worse, you said it's 4 days a week, that leaves 3 days a week you can get in some more exercise/walking/hiking/ taking her places.
Right now, she's young, so yes she's going to be bouncing off the walls at nite.
There are MANY people that work full time, and probably don't get in nearly what YOU are getting in already..
Things will get better as she matures. These dogs can be so adaptable to a schedule (like you have her on), so don't feel guilty.
Does she seem unhappy?? I'm sure she's a wild little thing, but hang in there, give it time. You sound like your doing the best you can with what you've got and it doesn't sound like she is "lacking" ..
Maybe after she feels better, see if you have adoggie daycare in your area, even ONE day a week can be a good work out..
Again, don't feel guilty, your doing more than many could probably do working full time
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