I've not been on this ship but have recently had a 160sq ft cabin on Fred Olsens Black Watch which comfortably slept all 4 of us,(two youngsters , two adults) the only gripe was the headroom on the upper berths (dropdown pullman types)was limited so getting in and out of bed was a bit of an event , also the side bars on the top berths were very small so we decided to put the kids on the lower berths in case they fell out of bed !!
Thank you for your response. It's helpful to know from someone who's been before. I hope you had a good cruise.