Help fighting a Medusa.

[Bazaku Ambrosuis]

Our group is playing rise of the runelords, and we are about to fight the final boss of the second book. We know she´s in the clock tower and know she can fly and likes to throw people to the floor but our gm said the boss is a little overpowered and the encounter will be very hard.
We plan on using lots of scrolls (we have spellcasters but we want to save spell slots for the fight) of bear's endurance , bull´s strengt, haste, false life, owl wisdom, fly, see invisibility, protection from evil and even a extract of true strike to each of us thanks to our alchemist. The alchemist also hast tanglefoot bombs so if he manage to hit her, she wont be able to cast spells.
May this be enough to kill her? or is a money waste in scrolls? Any advice?

[Captain Kuro]

Recon, recon, recon. Find some way to explore the clocktower first, either by invisible familiar, divination, capture/question minions, ect. My players used the first trick and ended up skipping the encounter, resulting in me having to move the encounter to later.

[_Ozy_]

You can cast spells while entangled with a concentration check. If you want to completely shut down spellcasting, you'll have to come up with something else.

[Imbicatus]

Smoked goggles are the best 10 gold you'll ever spend. +8 to saves vs gaze attracts is with the mini miss chance.

[Bazaku Ambrosuis]

Those lenses are great! Also a good recon, I'm going to ask the wizar to look at some spell that serves the purpose.
And for the spellcasting... May rage work?

[_Ozy_]

Silence is usually a good option to prevent spellcasting. Another good one is having someone right next to a creature with a readied attack and/or AoOs.

Arcane Eye is a good scouting spell, though it's 4th level. Maybe get a scroll?