"We're pretty convinced it's going to come in one of those two months," she said, referring to recent commentary from a host of Fed officials hinting that the economy is strong enough to withstand a bump in the short-term fed funds rate.
She said the Fed may pause in June and raise rates in July as the Brexit vote takes place roughly one week after the central bank's June meeting.
"Why take that global volatility risk?," Sonders pondered, referencing the concern that the UK exiting the European Union could fan fears of global uncertainty.
The markets are pricing in a 30% probability of a June rate hike and a 58% chance of a July liftoff.
"Given that the market has resumed its rally in the face of a Fed very clearly telegraphing that a (rate hike) is coming, that tells you that things are a little bit different now than in December, when the Fed last moved," Sonders added.
She said the market and Fed are aligned in terms of the number of rate hikes on the horizon, which was not the case in December, when central bankers expected four rate hikes in 2016 and the market expected no more than two.
According to Sonders, a wild card during the second half of 2016 is the "unique" presidential election. "That comes into play as a volatility factor that could potentially offset some of these more positive trends," she added.
From a sector perspective, Sonders has an outperform rating on technology and financials, with the latter fitting into Charles Schwab's view that multiple rate hikes will be coming this year. "Valuation is still very reasonable with financials," she said, adding that the same can be said for the technology sector.
The S&P 500 financials sector lost 0.5% since the start of the year, while the technology sector is roughly flat. The S&P 500 gained 2.2% year-to-date.