You can bf for as long as you and bub want.
You can express milk before or after work or when your on break and keep it frozen or in the fridge for bub to have when your not there. Saves you buying formula, keeps you bf and keeps you comfortable (when you stop breastfeeding your breast wont automatically stop producing milk so can get over full and sore).
PERSONALLY thats what id do. Its less fuss and costs less and you still get to spend that lovely time with bub.
You might find that if your baby hasn't had a bottle before she might not take to it very well for a while so id suggest getting someone else to feed her with breast milk from a bottle for a while before you go back to work. Not every feed but the ones she will be bottle fed when your working.
With my dd I always offered her milk one hour before a meal. For example at 7 months her routine looked a bit like this
7am -wake up and bottle
8am - breakfast (usually baby cereal,fruit,yogurt or toast)
10am - sleep
11:30 - wake and bottle (I would allow her to sleep up until 12 but any later and it mucked up arvo)
12:30 - lunch (I always gave one savory followed by one sweet at meals so maybe mashed vege followed by puree fruit)
4-4:30pm - wake up (small snack if she wanted)
5pm - tea
6:45pm - cuddle, bottle and bed
Thats just to give you a rough idea of how I did solids. I watched dd for signs she was ready to drop a milk feed like fussing, not drinking as much, eating more solids, sleeping through milk feed times. When she was ready I offered half the amount of milk and it got to the stage she just pushed it away.
Dd is 18 months now and has a bottle in the morning of cows milk and another before bed at night. The morning one she is starting to drink alot less so we are switching to a cup of milk with breakfast.
Hope I've helped.
OOOHHH... INTERNET FIGHT. WHAT ARE YOU GONNA DO? CAPS LOCK ME TOO DEATH?
(Noddy's not fat ffs!)