Do you need a lawyer for a DUI in California?

my 31 yr old (baby) sister recently got a dui (blew 0.13)...she got one 13yrs ago on her 18th bday. she’s also currently on chemotherapy…and normally doesnt drink..but something possessed her too that night. not judging. i just wonder if the chemo affected her b.a.l. etc….i’ve read where if its been over 10 yrs…its treated as first offense…anyone have any useful info i can pass along?