If Markam left her house about 1:04, then at 1:06 she is almost halfway to where the bus stop is, then she would have had arrived at about 1:08, about 4 minutes before the 1:12 bus arrives "on time" as McWatters WC testimony suggests the protocol for bus was to arrive not too early nor late, but "on time" as scheduled.
Markam is a routine bus rider and she is dependent on a bus arriving if she is to get to work, so she could opt to take either the earlier 1:12 bus or the later 1:22 bus. (presuming these 2 bus time are actually correct?)
The safe bet, to MAKE SURE she gets to work is to opt for the earlier bus, since that way, if that 1:12 bus does not arrive, then she will not miss work, since she can then wait still at the same bus stop and catch the 1:22 bus.
If it is the 1:22 bus , then either Markam has opted to wait for a rather long period of 14 minutes for this bus to arrive, or her clock is out of sync with both DPD official clock time AND the Bus company official time and probably her place of work clock too, by about 6 minutes. Her watch is set 6 minutes slow.
She has also opted to take risk of MISSING work altogether that day, should the 1:22 bus no arrive due to mechanical failure, flat tire, etc.
Bowleys watch must be set 6 minutes slow, if Markams bus is the 1:22 bus.
The more probable scenario, imo, is that both Bowley and Markam, being routine regular workers at workplaces that most likely had their clocks set by "official time" thus in sync with DPD clock, Bus Comany clock, TSBD Roof Top Clock, would NOT LIKELY have their own clocks runnng 6 minutes slow.
Also, imo, its more probable that Markam would opt to take the earlier 1:12 bus, and arrive at that bus stop about 1:08 having to wait only about 4 minutes if its on time and only 3 more minutes if its a little late arriving at 1:15, which it may occasionally have done.
Also, its a safer option, just in case the 1:12 bus breaks down and never arrives at all, Markam can still take the 1:22 bus, still make it to work, albeit possibly a little late, but better than missing work altogether for that day.