
Hi Dianne,
My old labrador bitch used to do this when we got home - it's involuntary so please ignore it. She's just so pleased to see you again she literally can't contain herself! Our bitch grew out of it, and until then we made sure she was always outside when we greeted her...we'd open the backdoor and call her outside, so it didn't matter if she puddled. The calmer you can be with her, the more relaxed she'll become and then I'm sure she'll improve.
Of course if you're worried you should get your vet to check that she hasn't got any urinary infection, but I would guess this is purely down to her pleasure at seeing you again. She may be going through a fearful, unsettled phase where she's not completely sure of her security with you, so make sure you don't overindulge her - just treat her as normal, carrying on your basic training, and she'll settle again soon.
Hope this helps, Good luck :)