We are having some problems with potty training. She knows she has to pee outside, but especially at nights when daddy comes home, she gets excited and drops a few . Then after 30 min or so I found that she pees on the couch or on her bed (a softer place). She knows she did something bad, she knows that I am upset and she scares. But she is still keep doing it. She is more scared now and pees more often, but with treats I could not have any success.. More she scares, more often she pees, if she doesn't scare she still pees.. I don't know how to handle with this? I need some help...

Most puppy don't know how to control there bladder yet, my dog took about a year until she stopped peeing from excitement, and as for the couch, the fabric probubly feels like whatever she is training to pee on, (mainly soft surfaces). Does it live inside or outside?

Just as human toddlers and children, dogs go through developemental phases..
That (7-9 months) is about the age a dog becomes aware of his vulnerability, and begins to pee where the scent of his or her pee is covered by the master's, his protector.. they sense that the unknown 'boogieman' can find them by their scent, so disguise it by peeing on the bed or couch where the protector's scent is the strongest..

It will happen most after any stress, such as being scolded, left alone, or even after a nightmare..
They do tend to outgrow the behavior as they mature, and gain more self confidence and security.