Which integrated amplifier .

So very sad to hear of your plight. Had a close friend pass of the same lung cancer 10 years and I miss him all the time. We shared interests in music, audio, computers, food and wine and travel. Best adult friend I ever had. I am familiar with your speakers and suggest the Marantz PM8006 of which I have had the 8005 for 5 years. The amp has plenty of current and alternately drives Spendor S3/5s at 84DB, Kef R300s and Ohm Walsh 2-100s. It performs quite ably on all and delivers far more volume than my 62 year old ears need and I listen to everything from classic rock, alternative, jazz, classical, acoustic music, Hawaiian, world, etc. I also play blues guitar and will often play along plugged in...it is able to handle clearly Muddy Waters, Hendrix, Buddy Guy etc. It comes with a 3 year warranty whcih I have never had to use and is very well made in the Japan Reference factory of Marantz. It also has both a Direct Mode and tone controls covering Treble, Mid and Bass which is good for old lousy recordings that need help and for live recordings of which I have lots. Comes with a remote which makes it easy to change things. It is decent looking and very intuitive to use. Sound is slightly warm but has enough detail and dynamics to it that it compares well with my other amp a rebuilt McIntosh MC250. It can be had for under $1000 online. 
Good luck, best wishes and aloha. 

Musical Fidelity M3si. $1500 and a great match for Maggies.

I've read great things on on Musical Fidelitys new integrated .

Maybe you could work out a deal for something with TMR Audio for an agreeable trade.

First and foremost I’m so sorry to hear of your situation — it truly makes my heart break. Over the years through personal experience I’ve become very disappointed with doctors’ general ability to make a correct diagnosis and/or identify the best possible treatment. I say this in the hope you’ve gotten or would be open to at least getting a second or even third opinion. Sorry but just felt I had to at least mention this.

On audio, I focused mainly on options that financially may be most viable yet also likely more than acceptable to your daughter.

Option 1: There’s a NuPrime IDA-8 integrated on US Audio Mart for only $650, and you can likely get more than that selling your DNA-125 here. It puts out 100Wpc into 8 and 4Ohms, which may be plenty for your daughter, and it also has a nice onboard DAC that she can use if/when she decides to stream music without adding another box. It’s also small, simple, and attractive, which your daughter would also likely appreciate. Reviews are very positive and I believe it even won a Product of the Year award some years back, FWIW. If you think this is an attractive option but not sure if it’s enough power, there’s also an IDA-16 on eBay for $1700 (or you can bid less) that puts out double the power with even sleeker looks.

Option 2: As an owner of a DNA-0.5 Rev. A I can certainly appreciate why you’re fond of your amp. I’m not sure having a separate preamp is really that much of a burden as long as that pre is solid state so she doesn’t have to mess with tubes. If you agree, there’s a McCormack MAP-1 available here for $700 that would obviously be a good sonic match with your amp, and aesthetically it would match perfectly as well — again something she’d likely appreciate. And if she ever got more into audio and wanted something better she could send either or both McProducts off to SMcAudio and have Steve transform them into reference-level pieces of equipment.

Anyway, just a couple more economical possibilities you might want to consider. Best wishes with everything.