Cass, are you happy to keep giving her the pentavite? It certainly won't harm her. Millions of adults take a multivite 'just in case' every day. I know I do and I'm very particular about my diet.
The iron is probably useful in keeping her appetite up too.
All babies are different and what was good 20 years ago, isn't always whats best for one baby right now.
You are doing a fab job. Trust your gut.