Toddler (2 yrs 5 mths) sudden nighttime settling problems

Our daughter has started being difficult at nighttime when we try to put her to sleep. We had another baby 5 months ago, but our older daughter's behaviour only started about a month ago when we had to convert her cot to a toddler bed. We first had a bedguard on the front to stop her from falling out (very low to the ground) and have now taken that off and placed a mattress in front of the bed in case of falls.

Our bedtime routine is normally getting into PJs, then two books and milk, then brushing teeth, a night song, a tummy rub, then goodnight. More so with my husband than me she is starting to act up when it's time for tummy rub, won't lie down, he has to warn her that he will leave if she does not lie down, she normally doesn't and he leaves.

She then proceeds to being restless, calling us via the monitor when she has done a poo (no interest or activity with potty yet), then wants a drink, a tummy rub - but still not lying down, playing with her doll and teddy, singing, talking, sitting in odd spots in her room etc.

Usually it has taken from around 7pm starting nighttime procedures to around 9pm to have her finally settled and it's not only disrupting our dinner time but also the baby's sleeptime.

Has anyone got any suggestions, advice on what we are doing wrong or could do better, differently??javascript:emoticon('](*,)')