Jessica Alba feels she is ''missing moments'' with her children because she's always working.

The 36-year-old actress - who has two daughters Honor, eight, and Haven, five, with her husband Cash Warren - has opened up about the struggles of being a working mother, and admits she often feels guilty for missing key ''milestones or moments'' with her brood.

Speaking to E! News with her showbiz pal Jenna Dewan Tatum, the 'Good Luck Chuck' actress said: ''I think feeling like you're missing moments, like, well first off, you feel bad when you realise they are wearing shoes that hurt them because you're like, 'Oh, I didn't even realise that you've been wearing shoes that are too small for you for like 3-4 months, my bad.'

''Some of those milestones or moments, you want to be there for every single one and it's not realistic when you're working, but for me, that's what gets me. Even the everyday little things like picking them up from school are a big deal, so I drop them off at school most mornings and try to get home for bedtime. But the weekends is really when I get to spend the time with them.''

Jenna - who has four-year-old daughter Everly with her husband Channing Tatum - echoed her statements and said figuring out the right ''balancing act'' between work and family was one of the ''toughest parts'' of parenting.

The 'Step Up' star, also 36, said: ''Yeah, for me it's always a balancing act and learning and perfecting the balancing act is the toughest part. For me, with work, it's interesting because it will be really, really busy and then I'll have a little bit of time where it isn't quite as busy, so you have a little bit of time where balancing that is easier. She's pretty good now because she understands that now.

''It's like a checks and balances kind of thing where you really put in good quality time so you feel a little bit better about working the next day. It's about finding that, and constantly sort of not making yourself feel guilty but trying to work that out for yourself, so that your family gets lots of time and quality time together. It's a balancing act always.''

Jessica added that for her, she aims to value ''quality'' of the time spent with her children over the ''quantity''.