Sporty1977 I don't have much advice but you are not alone!
DD is great at self settling and sleeping until I put her down at the 4/5pm time where she will only ever cat nap which is really hard when I am organising DS and as they are not quite 15 months apart, that time of the evening can be extremely difficult, especially when DH is away for work. She is also a 3-hourly feeder, like clockwork - on time every time :-)
DS also likes his routine of bath at night so if DD is unsettled I either put her in the manduca while I do dinner, bath etc or put her in her bouncer and bring her into each room with me and she's usually fine so long as she's able to see us.
I guess the main way I 'cope' with it when I'm alone is just do what makes her happy, if she just will not sleep then I get her up, if she is hungry (which usually she isn't) I feed her, if she just wants to be up and joining in the chatter at dinner time and the giggles and splashes in the bathroom with DS and I (which us usually the case as she will just sit there with a big smile on her face when she's with us) then that's what I do to make her happy. It was hard for me to get out of the 'but she should be...' or 'but she needs to be...' mentality, as I'm a planner/routine person by nature but I had to just relax and go with it as you are doing
All the best!
Edited by MrsEmma