Sorry, I'm not very well informed about current affairs, but here are my humble offerings.
The only celebrity I can really cite as a 'role model' is probably JK Rowling for her talent, and she comes across as down to earth and just generally nice. I found it inspiring to hear about how she used to write in cafes with her daughter in a buggy and all the work she has done since becoming famous for single parent families.
I admire Davina McCall for all the reasons already mentioned, and her work with the NCT helping to promote home birth. Salma Hayek for breastfeeding that baby in Sierra Leone. Various musical artists whose work inspires me in a feminist way: KT Tunstall, Ani DiFranco, Amy Lee.
Non celebrities - I probably look up to these people more, just because I have personally met them and know them more. I don't know whether it's particularly helpful to you but I'll include them anyway.
My Mum - brought up me and my sister on her own on very little money, while suffering with M.E. and never once let on how she really felt about my Dad despite him letting us down constantly. Always respectful and I think did a good job 
My antenatal teacher - has now left the NCT and set up her own business, including offering free early pregnancy classes to people who are otherwise unlikely to take any classes, which can't be making her very much money. Wonderfully non-judgemental and non-patronising in her approach.
Someone from toddler group who has had every kind of shit you can imagine thrown at her and has walked tall, brushed it off and gone on with her life, and is a genuinely lovely person to boot. I don't want to say too much more but she is amazing, truly inspirational.