I am so sorry.
Sadly, yes, I have had to deal with PLE and also PLN. I lost my PLE pup, Cookie, in March of this year....but, she passed from Lymphoma, not the PLE; BUT the PLE had been an issue for the past 6 months or so and she was on high doses of prednisone. My Olivia just passed from PLN...in the end they felt she also had PLE but it was never diagnosed. She had been diagnosed in 2013 and had a few bad episodes, but basically did really well over those years. Cookie did since 2011. So, there are success stories...they can rebound sometimes.
Sometimes you can get them to turn around. Cookie was admitted to ICU a few times and was given Hetastarch...it does work sometimes but not always. I will pray that it helps your girl. Actually, it probably is a wee bit promising that her albumin is .1 which is up from .08. The normal is very low...so any trend upwards is a good sign.
As for letting her go....I have walked that path many times and it is just so hard. All I can say is that I believe when it is time, they really do let you know.
I am going to say some extra prayers for you and your husband....and for your sweet Bella. She still may turn around....I have seen some of these PLE pups be really really sick and then bang...they start to get better. One of our YT members had a really sick one a few years ago ... she was refusing to eat and really going downhill. I suggested Mirtazapine and all at once she started eating and then responded to her treatments.. She is still doing well. She had PLE but it was from a fungal infection. My Cookie was .08 and turned around....so let's just keep positive thoughts.
Please keep us posted. I totally get it about the money...I would trade my house to have my Cookie back again.