Yes but apparently she was not in the relationship any more and was having a some kind of relationship with DM.
Which creates a jealousy motive for both killing LB and framing DM.
I am not at all making an accusation against SL with this line of thinking, I just like to see every question asked and answered, and hope LE is exploring this angle too.
Things that don't make sense if DM was framed by SL/SL killed LB:
- Identification of DM's tattoos on first test drive
- Why would SL do a first test drive with the same vehicle as TB?
- SB is a witness to DM being present on test drive with TB, I would imagine she'd be able to rule out that it was SL and not DM
- SL would have to be aware of DM's property in Ayr to plant TB's body there (possible)
- SL would have to be aware of his mother's property in Klineberg to know to leave DM's trailer there (very unlikely IMO)
- SL would have to have access to DM's trailer to put TB's truck in it
- SL would be the driving force behind repeatedly trying to bring attention to a missing person's case which is not being taken seriously by police and not investigated as a homicide