I agree, that was my first thought, 20-25 minutes would be enough, (especially if / when the summer arrives and its warm 😉 ).
It sounds as if both the barking and problem with the walking are signs that her confidence needs building up, which at her age us really quite normal. The main thing is to stay calm and be patient, you could pat your leg and put a jolly voice on to encourage her to walk with you and then praise and reward when she does - even if you only get her to go a few yards, the important thing is, she learns to do it of her own free will so that she gains self confidence.
Practice leaving her by shutting the door for a few moments and then praising and rewarding when she's quiet.
Any sort of training, games etc where she's praised for good behaviour will help her to learn what's expected of her and will boost her confidence (sorry if I keep repeating the same word, but I can't think if another way if putting it!). She's still a baby and some dogs just need a bit more encouragement to stand on their own four paws, try not to get anxious though as she'll pick up on that too. Good Luck!!
