Nurses working at Letby's previous hospital would certainly see babies die. Liverpool Women's Hospital is a large specialist intensive care unit which sees several infant deaths a month. Lucy Letby had trained there in resuscitation methods, since it was an acute enough unit to have a dedicated resuscitation nurse whom she could shadow.
You see, once you blur the details, you can make anything seem sinister. But it doesn't stand closer examination.
"Getting straight back on the horse" - keeping busy and facing the challenge - is a very well-known coping method. Letby's friend who was texting with her has obviously been unhappy with the way that conversation has been twisted. She wrote in her Thirlwall submission that all she meant is that she herself wouldn't find that method helpful. That's fine, obviously. We all cope with stressful situations differently.
Letby wanted to be in room 1 (the intensive care room) looking after a vulnerable baby that night. She had a right to want this. And she was right to want this. The nurse put in charge of that baby was not qualified to offer one-to-one intensive care, and that very fragile baby needed one-to-one intensive care by all guidelines. The unit broke staffing guidelines, despite the baby being one of the smallest they had ever cared for and never having been examined by a consultant.
I have no idea why someone planning to murder an infant would insist on having direct care - they all babysat for each other anyway during breaks, so it would be no obstacle. And draw that wish to everyone's attention?
You only need to take the exchange at face value - she wanted to work in the intensive care unit (and should have been).