Hi Beansmum, I've taught in unis for years and it wouldn't enter my head that you were mature until you were in your 40s at least!
What I would do though is make sure that the support networks are there--ask the level one (first year) tutor what support there is. Then ask if you can talk to a mature student, with children, who is graduating now. They can give you the info on the practicalities and flexibilities of the programme. (And they'll love to do it as they'll be rightly proud of having worked their way through the whole process themselves.) A student on the programme will also be able to tell you about any formal or informal support networks that exist.
Also, find out now if possible when core lectures are in the first year. Depending on your degree programme you'll usually find that there are core compulsory sessions and then other tutorials or seminars where there are more options re time slots (depending on how your degree elements fit together). The tutor might even let you pre-register for the best slots if you get in touch now
I made sure on the last two programmes I organised that core slots were within school hours so between 10 and 2, where possible, and 10 and 3 otherwise. This fairly obvious way of helping student parents is not general policy though and being forewarned about parenting/college clashes is being forearmed.
Find out now too about options for deferring for a year, switching between full and part time etc. as life will have its ups and downs over five years.
When the inevitable happens and you need to miss a day to deal with a domestic hitch, ask lecturers for printouts of lectures/handouts (again, many won't think of offering this as routine). Make yourself known to the tutors, and involve them as soon as an issue of balancing study/life arises and they'll be in a better position to help than if you battle on by yourself.
Their buzzword is 'retention' so they should go all out to help you manage the programme, whatever crops up.
This might all sound a bit negative, but planning ahead, being realistic, and 'allowing' yourself to feel freaked out by going back to learning, especially in the first year, is what gets student parents through in my experience.
You will have a fab time, make fantastic friends and make your family v. proud! Good luck with everything.