I sympathise, but she's entitled to a holiday like anyone else.
I do however think pregnant women should have the same midwife for all her checks, with the exception of being off due to being sick. Having the same one ensures continuity of care, actually caring for the patient, rather than seeing a number on a sheet. I know this is not possible in labour but for the months up to the labour it should be.
For my first 3 children I had the same midwife, I really felt like she cared. She remembered me when I saw her,i felt like I could be open about any emotional problems not just physical.
For my 4th child I was dismayed at having a different midwife for every single appointment. Apparently they were in the middle of recruiting, took a year to fill the post at least perhaps more since I no longer required the service so I'm not aware of that. They were lovely but to be honest I felt like a piece of cattle patient 004 lets do blood pressure, height,weight, prod belly chart it up, urine check ok off you go, next!it got to the point I'd skip appointments I just didn't care, because I felt like they never cared.
I wouldn't advise you to be stupid like me don't miss your appointments, ok you may not get the personal service but you still get the all important check up.
I was glad when the midwives left me alone with the baby to be honest I hate the home visits.