Hi there Raya
If you would like to go shark cage diving in Gansbaai, it does not take all day - usually only half a day. The operators go out more than once a day, so you could do the morning trip and husband the afternoon trip.
I would not recommend that you take your daughter on the boat with you at this stage. There will be many more opportunities when she gets older!
As a mother of 3 daughters, I can relate to your concerns and had to "sit on the side" on numerous occasions until they grew up and were able to join us on our diving expeditions. But, there is light at the end of the tunnel and before you know it, you will be diving as a family!!
There is plenty of nice accommodation in Kleinbaai (where the shark boats leave from), so you can choose to stay for as many nights as you like.
Once you have had enough of the sharks, come and dive with us! We don't have accommodation on site but again, lots of accommodation options waiting for you in Gordon's Bay too.
There is fantastic year-round diving in the waters around Cape Town. We have an exciting dive with Sevengill Cowsharks in Simon's Town and there are some great historical wrecks and beautiful reefs and kelp forests too - you will be amazed.
If you need any further information, please shout!
Best wishes
Kate