Ofc Letby is not Allitt but I noticed that Allitt's offending including casual attacks such as putting a pillow over a baby's face.* (Allitt didn't have access to ICU and her victims were older babies and young children but the impulses seem similar)
* That was from the show below.
I can't put the Youtube urls up due to TOS but if you search for show titles you can find examples like this one below. It's a BBC dramatisation but it seems to be in line with the case facts I'd seen in a straight documentary.
Angel of Death : The Beverley Allitt Story (2005)
I know you're interested in the psych aspects the LL case, so if you do watch it, it also covers the period while she was on bail and temp living at a friends. Attempts to poison dog, the brother and to simulate poltergeist activity to create as much havoc as possible.
or Trevor McDonald and the Killer Nurse
ITV traditional documentary on BA case focussing mainly on the investigative team, interviews the LE involved and BA's adult surviving victims, a retrospective. Incl some of the interrogation tapes.
(PS The two consultants who saved many lives were thrown under the bus, sacked. Lead detective had a major battle to build a case, against naysayers who said he'd never get there)